A metal wire is uncharged. Explain how it is possible for a current to flow through it.
Answer:
Most conductors are fully charge neutral when carrying current, since their atomic structure is not altered, and electrons are in their normal state of jumping from atom to atom all the time.
It is just that this movement gets a direction under an external electric field, which causes a net charge flow (current) in conductor. So the conductor remains uncharged.
It is however possible for a capacitor plate to be charged (charged capacitor), and at the same time the plate can be a part of current carrying circuit through two points on it. In this case, charge on plate is independent of current and unrelated with it.
I have made foil type capacitors with such construction where the capacitor was a part of filter circuit in a signal carrier circuit, and connections were made from both ends of each foil.
what is mean by combination reaction ?
[tex] \underline{\purple{\large \sf Combination \: reaction :-}} [/tex]
Those reaction in which two or more substances combine to form a one new substance are called Combination reaction
In this reaction, We can add :
Two or more elements can combine to form a compound.Two or more compounds can combine to from a one new compound.An element and a compound can combine to form a new compound.[tex] \underline{\green{\large \sf For\: example :}} [/tex]
[tex] \sf 2H_{2} + O_{2} \: \underrightarrow{Combination} \: 2H_{2}o[/tex]
In this, Hydrogen is an element and Oxygen is another element. Both are combined to form compound 'Hydrogen oxide'. Hydrogen oxide is commonly known as water.
Match the scienntist with their accomplishment / discoveries
Answer:
newton - motion, gravity
kepler - orbital paths
brahe - the sun goes around the earth
Explanation:
im not sure about brahe but its the only one that makes sense
A bicycle has a momentum of 36 kg* m/s and a very!I city of 4 m/s.What is the mass of the bicycle?
p = 36 kgm/s
v = 4m/s
we know that,
p = mv
so,
[tex]m = \frac{p}{v} [/tex]
[tex]m = \frac{36}{4} [/tex]
[tex]m = 9kg[/tex]
Bill and Janet are pulling on opposite sides of a table. Bill pulls with a force of 250 N to the left, and Janet pulls with a force of 325 N to the right. What is the net force on the table?
Answer: 75 N to the right
Explanation:
When two forces acting in opposite directions, they will cancel in magnitudes. Here, the net force acting on the table is 75 N to the right.
What is force?Force is an external agent acting on an object to change its motion or to deform it. Force is a vector quantity. Hence, it is characterized by a magnitude and direction.
If two equal forces are acting on object from the same direction, they will add up in magnitudes and the net force is their sum. If the two forces are from opposite directions, they will cancel each other in magnitude and the net force will be the substracted value.
Here, Bill is pulling by 250 N to the left and Janet is pulling to the right by 325 N. The force is not balanced because they are unequal.
net force = 325 - 250 = 75 N
The larger force is to the right. Hence, the net force is 75 N to the right.
Find more on net force:
https://brainly.com/question/13410291
#SPJ2
Find the current if 55 C of charge pass a particular point in a circuit in 5 seconds.
Answer:
The current is 11 Amperes
Explanation:
Electric Current
The electric current is defined as a stream of charged particles that move through a conductive path.
The current intensity can be calculated as:
[tex]\displaystyle I=\frac{Q}{t}[/tex]
Where:
Q = Electric charge
t = Time taken by the charge to move through the conductor
The current intensity is often measured in Amperes.
The charge passing through a point in a circuit is Q= 55 c during t=5 seconds, thus the current intensity is:
[tex]\displaystyle I=\frac{55}{5}[/tex]
I = 11 Amp
The current is 11 Amperes
The speed of sound in air is 10 times faster than the speed of a wave on a certain string. The density of the string is 0.002kg/m. The tension in the string is __________.
Answer:
The tension on the string is 2.353 N.
Explanation:
Given;
the speed of sound in air, v₀ = 343 m/s
then, the speed of sound on the string, v = 343 / 10 = 34.3 m/s
mass per unit length, m/l = μ = 0.002 kg/m
The speed of sound on the string is given as;
[tex]v = \sqrt{\frac{T}{\mu} } \\\\v^2 = \frac{T}{\mu} \\\\T = v^2 \mu[/tex]
where;
T is the tension on the string
T = (34.3)²(0.002)
T = 2.353 N
Therefore, the tension on the string is 2.353 N.
A heat pump has a coefficient of performance of 3.85 and operates with a power consumption of 7020 W. How much energy does it deliver into a home during 1 h of continuous operation?
Answer:
97.3 MJ
Explanation:
The formula for the coefficient of Perfomance is given as
COE = Q/W, where
COE is the coefficient of Perfomance
Q is the heat provided
W serves as the work input.
Dividing both sides of the equation by a factor of time t, we get the coefficient of Perfomance in terms of heating power and input power, so we say
COE = P / P(i),
making heating power, P the subject of formula, we have
P = COE * P(i)
P = 3.85 * 7020 * 1 * 3600
P = 97297200 J
P = 97.3 MJ
Help me please,
A ball is thrown straight up in the air. What is the velocity and acceleration at the top of the path?
A) v 0m/s, = 0m/s/s
B) v = 0m/s, a 10m/s/s
C) v = 10m/s, a 10m/s/s
D) v = 10m/s, a = 0m/s/s
E) None of the above
Option B
Explanation:
no distance was given only the acceleration due to the fact that it went up (10m/s/s)
s0 it is
0 m/s and 10m/s/s (option B)
According to Steinberg, which of the following statements is true about creative people
They appreciate art and music.
They always take popular stands.
They accept ideas at fàce value.
They accept their limitations,
A 2150 kg car, moving east at 10.0 m/s, collides and joins with a 3250 kg car. The cars move east together at 5.22 m/s. What is the 3250 kg car’s initial velocity calculated to the nearest tenth? Record your answer in the boxes below. Be sure to use the correct place value.
Answer:
2.1 m/s
Explanation:
According to law of conservation of momentum;
m1u1 + m2u2 = (m1+m2)v
m1 and m2 are the masses
u1 and u2 are the initial velocities
v is the common velocity
Given
m1 = 2150kg
m2 = 3250kg
u1 = 10.0m/s
u2 = ?
v = 5.22m/s
Substitute and get u2
2150(10) + 3250u2 = (2150+3250)5.22
21,500 + 3250u2 = 5400(5.22)
3250u2 = 28,188 - 21500
3250u2 = 6688
u2 = 6688/3250
u2 = 2.1 m/s
Hence the 3250 kg car’s initial velocity has an initial velocity of 2.1 m/s
Define conductor and insulator, including how the resistance is different in the two, and give at least one example of each.
Answer:
Those substances which can conduct electricity are called conductors, while those substances which don't conduct electricity are called insulators.
Resistance is the obstruction provided by the material through which the current passes,so since conductors conduct electricity and insulators don't,so the obstruction i.e resistance provided by the conductor must be less,while insulators being unable to conduct electricity,has very high resistance.
Example of conductor is copper
Example of insulator is plastic
Two motorcycles are traveling due east with different velocities. However, 3.63 seconds later, they have the same velocity. During this 3.63-second interval, motorcycle A has an average acceleration of 4.55 m/s2 due east, while motorcycle B has an average acceleration of 18.9 m/s2 due east. (a) By how much did the speeds differ at the beginning of the 3.63-second interval, and (b) which motorcycle was moving faster
Answer:
52.095 m/s
Motorcycle a was moving faster
Explanation:
We start by using one of the equations of motion
V = u + at
If the first motorcycle starts with an initial speed of u(a) and accelerates at a value of a(a) = 4.55 m/s², then the final speed after a time of 3.63 seconds is V(a). We then represent it as
V(a) = u(a) + a(a).t
If the second motorcycle starts with an initial speed of u(b) and accelerates at a value of a(b) = 18.9 m/s², then the final speed after a time of 3.63 seconds is V(b). We then represent it as
V(b) = u(b) + a(b).t
Assuming that the final speeds v(a) = v(b), and then subtract the equation of the second motorcycle from that of the first, we have
0 = u(a) - u(b) + a(a).t - a(b).t
-u(a) + u(b) = a(a).t - a(b).t, on rearranging, we have
u(b) - u(a) = [a(a) - a(b)]t
Since we have the values for acceleration and the time, we substitute so that
u(b) - u(a) = (4.55 - 18.9)3.63
u(b) - u(a) = -14.35 * 3.63
u(b) - u(a) = -52.095, or we rearrange to get
u(a) - u(b) = 52.095 m/s
*
If a rock falls for 3 seconds off of a bridge, how far will the rock fall?
-30 m
-45m
-60m
-75m
How would the mass and weight of an object on the Moon compare to the mass and weight of the same object on Earth? * Mass and weight would both be less on the Moon. Mass would be the same but its weight would be less on the Moon. Mass would be less on the Moon and its weight would be the same. Mass and weight would both be the same on the Moon.
Answer:
B. Mass would be the same but its weight would be less on the Moon.
Explanation:
The mass of a body can be expressed as the quantity of matter it contains. While the weight of a body is the extent of the gravitational force impressed on the body by a massive body.
Thus, the mass of a body is constant either on the Earth or on the Moon. But the weight would be less on the Moon because the gravitational force on the Moon is far less than that on the Earth. Therefore the weight would be less on the Moon.
The appropriate option is B.
The mass will remain same on both moon and Earth, but weight will be lesser on Moon than Earth. Hence, option (B) is correct.
The prime focus to solve this problem is the mass and weight of an object. The mass of a body can be expressed as the quantity of matter it contains. While the weight of a body is the extent of the gravitational force impressed on the body by a massive body.
So, the mass of a body is constant either on the Earth or on the Moon. But the weight of an object will depend on the mass and the gravitational acceleration.
W = mg
Here, W is weight, m is mass and g is gravitational acceleration.
Weight would be less on the Moon because the gravitational force on the Moon is far less (due to lower value of g) than that on the Earth. Therefore the weight would be less on the Moon.
Thus, we can conclude that the mass will remain same on both moon and Earth, but weight will be lesser on Moon than Earth. Hence, option (B) is correct.
Learn more about the mass and weight here:
https://brainly.com/question/13040516
If your heart is beating at 76.0 beats per minute, what is the frequency of your heart's oscillations in hertz?A) 3.98 HzB) 4560 HzC) 2.54 HzD) 1450 HzE) 1.27 Hz
Answer:
E) 1.27 Hz
Explanation:
If the heart beats 76 times in a minute, this means that the time needed for a single beat (the period of the oscillation), is just 1/76 of a minute, as follows:[tex]T = \frac{1}{76} min = 0.013 min = 0.79 sec. (1)[/tex]
The frequency of the oscillation, by definition, is just the inverse of the period T, as follows:[tex]f = \frac{1}{T} = \frac{1}{.79sec} = 1.27 Hz (2)[/tex]
The right answer is the E).
Through what angle in degrees does a 33 rpm record turn in 0.32 s?
63°
35°
46°
74°
Answer:
1 rev = 2(pi) rad pi(rad) = 180 degrees
so 33 rev/min * 1 min/60s * (2*pi)rad/1 rev *180 deg/ pi rad * .32 s = 63.36 degrees
Explanation:
63.36 estimated to 63 so 63
The angle in degrees where 33 rpm record turn in 0.32 s should be considered as the 63 degrees.
Calculation of the angle:Since we know that1 rev = 2(pi) rad
So here pi(rad) = 180 degrees
Now for 33 rpm it should be like
= 33 rev/min * 1 min/60s * (2*pi)rad/1 rev *180 deg/ pi rad * .32 s
= 63.36 degrees
= 63 degrees
hence, The angle in degrees where 33 rpm record turn in 0.32 s should be considered as the 63 degrees.
Learn more about an angle here: https://brainly.com/question/3394547
A block of mass, m, sits on the ground. A student pulls up on
the block with a tension, T, but the block remains in contact
with the ground. What is the normal force on the block?
Answer a
Explanation: a
A popular ride at an amusment park lifts
customers up to a height of 50 m and then
drops them threw a displacement of 50 m
before slowing them to a stop. How fast
are the customers going at the 50 m
mark?
Answer:
[tex]31.32\ m/s[/tex]
Explanation:
[tex]We\ are\ given\ that:\\Height\ to\ which\ there're\ lifted=50m\\Displacement\ during\ the\ descent=50m\\Now,\\In\ order\ to\ find\ the\ velocity\ of\ the\ customers\ at\ 50\ m,\\We\ can\ use\ the\ Third\ Equation\ Of\ Motion,\ which is:\\2as=v^2-u^2\\As\ we\ know\ that,\\Acceleration\ due\ to\ gravity=9.81\ m/s^2\ or\ roughly\ 10\ m/s^2\\Displacement=50\ m\\Initial\ velocity=0\ m/s^2\\ [As\ they\ stop\ when\ they\ reach\ the\ maximum\ height\ of\ 50\ m\\ and\ begin\ their\ descent][/tex]
[tex]By\ reconstructing\ the\ Third\ Equation\ Of\ Motion,\ we\ have:\\2gs=v^2\\Hence,\\v^2=2*9.81*50 \\v^2=981\ m^2/s^2 \\v=\sqrt{981\ m^2/s^2} \\v=31.32\ m/s[/tex]
A carousel at the local carnival rotates once every 45 seconds.
(a) What is the linear speed of an outer horse on the carousel, which is 2.75 m from the axis of rotation?
(b) What is the linear speed of an inner horse that is 1.75 m from the axis of rotation?
Answer:
We know that the carousel does a complete rotation in 45 seconds.
Then the frequency of this carousel will be f = 1/45 seconds.
And the angular frequency will be 2*pi times the frequency, then we have:
angular frequency = w = 2*3.14*(1/45s) = 0.1396 s^-1
Now, the linear speed of an object that rotates with a radius R, and an angular frequency W is:
S = R*W
then:
a) in this case the radius is 2.75m, then the linear speed is:
S = 2.75m*0.1396 s^-1 = 0.3839 m/s
b) in this case the radius is 1.75m, then the linear speed here is:
S = 1.75m*0.1396 s^-1 = 0.2443 m/s
(a) The linear speed of an outer horse on the carousel is 0.384 m/s.
(b) The linear speed of an inner horse on the carousel is 0.244 m/s.
Given data:
The time interval for the rotation of carousel is, t = 45 s.
The distance of the outer horse from the axis of rotation is, r = 2.75 m.
The distance of an inner horse from the axis of rotation is, r' = 1.75 m.
(a)
The linear speed in this problem can be obtained from the concept of rotational mechanic, in which the ratio of the circumference and the time gives required linear speed. So,
v = 2 π r/t
Solving as,
v = 2 π (2.75) / 45
v = 0.384 m/s
Thus, we can conclude that the linear speed of an outer horse on the carousel is 0.384 m/s.
(b)
Now similarly the linear speed of an inner horse is calculated as,
v' = 2 π r' / t
Solving as,
v' = 2 π (1.75) / 45
v' = 0.244 m/s
Thus, we can conclude that the linear speed of an outer horse on the carousel is 0.244 m/s.
Learn more about the rotational mechanics here:
https://brainly.com/question/18303026
20 pts.
Which of the following statements is true?
O Electromagnets use electrlcity and magnets.
O Magnetic fields are strongest around the poles of a magnet.
O The south pole of a magnet will repel the south pole of another magnet.
O all of the above
Answer:
all are true so d is right
Explanation:
Electromagnets use electrlcity and magnets is true.
Magnetic fields are strongest around the poles of a magnet is true.
The south pole of a magnet will repel the south pole of another magnet is true
and since all of them is true the answer is d all of the above
PLEASE HELP ME ASAP!! GUYSSS!! I AM IN CLASS AND DYING! LITERALLY
Billy and Ashley live in the same time zone. Billy lives in Brazil (blue smiley face on the image below). Ashley lives in Eastern Canada (yellow smiley face on the image below).
One day, Billy and Ashley are both outside at 1:32 pm. They are talking on the phone to each other. As they talk, Billy notices the sky in Brazil getting progressively darker. Eventually, it feels like it is nighttime, because it is so dark. Billy thinks the world is coming to an end. He asks Ashley if she is experiencing the same thing in Canada. Ashley has no idea what he is talking about. “It’s perfectly bright and sunny where I am,” she says.
Ashley and Billy conclude that the world is not coming to an end. They reach out to some 7th graders to figure out what is happening. The 7th graders tell Billy that he is experiencing a solar eclipse. To help Billy and Ashley understand, create a model to show why Billy is experiencing an eclipse in Brazil, but Ashley is not experiencing the eclipse in Canada.
Your model must include:
The sun, the earth, the moon, and solar energy (clearly labeled).
How accurate your scale is.
How solar energy interacts with both the moon and with Earth.
The tilt of the moon’s orbit relative to the Earth’s orbit
Why Billy is experiencing the solar eclipse and why Ashley is not.
Answer:
sounds like a you problem
Explanation:
yeah
What would be the coefficient of performance if the refrigerator (operating between the same temperatures) was instead used as a heat pump?
COP =
Complete Question
A certain refrigerator, operating between temperatures of -8.00°C and +23.2°C, can be approximated as a Carnot refrigerator.
What is the refrigerator's coefficient of performance? COP
(b) What If? What would be the coefficient of performance if the refrigerator (operating between the same temperatures) was instead used as a heat pump? COP
Answer:
a
[tex]COP = 8.49[/tex]
b
[tex]COP_1 = 9.49[/tex]
Explanation:
From the question we are told that
The lower operation temperature of refrigerator is [tex]T_1 = -8.00^oC = 265 \ K[/tex]
The upper operation temperature of the refrigerator is [tex]T_2 = 23.2 ^oC = 296.2 \ K[/tex]
Generally the refrigerators coefficient of performance is mathematically represented as
[tex]COP = \frac{T_1}{T_2 - T_1 }[/tex]
=> [tex]COP = \frac{265}{296.2 - 265 }[/tex]
=> [tex]COP = 8.49[/tex]
Generally if a refrigerator (operating between the same temperatures) was instead used as a heat pump , the coefficient of performance is mathematically represented as
[tex]COP_1 = \frac{T_2}{ T_2 - T_1}[/tex]
=> [tex]COP_1 = \frac{296.2}{ 296.2 - 265 }[/tex]
=> [tex]COP_1 = 9.49[/tex]
The coefficient of performance if the refrigerator is used as a heat pump is 9.5.
The given parameters;
initial temperature, T₁ = -8 ⁰C = -8 + 273 = 265 Kfinal temperature, T₂ = 23.2°C = 23.2°C + 273 = 296.2 KThe coefficient of performance if the refrigerator is used as a heat pump is calculated as follows;
[tex]COP = \frac{T_2}{T_2 - T_1}\\\\COP = \frac{296.2}{296.2 - 265} \\\\COP =9.5[/tex]
Thus, the coefficient of performance if the refrigerator is used as a heat pump is 9.5.
"Your question is not complete, it seems to be missing the following information";
A certain refrigerator, operating between temperatures of -8.00°C and +23.2°C, can be approximated as a Carnot refrigerator.
What would be the coefficient of performance if the refrigerator (operating between the same temperatures) was instead used as a heat pump?
Learn more about coefficient of performance here: https://brainly.com/question/20713684
PLEASE HELP :(
I WILL GIVE EXTRA POINTS
1. When is the kinetic energy of an electron transformed into potential energy?
when it interacts with other electrons, decreasing its speed
when it interacts with neutrons without changing its speed
when it interacts with neutrons , increasing its speed
when it interacts with other electrons without changing its speed
2. Atoms bond to form molecules. Which structures or regions of the atoms interact in bonds ?
electric fields of particles with positive charge
electric fields of particles with no charge
electric fields of particles with negative charge
electric fields of particles with opposite charges
3. If two electrons that are apart get pushed toward each other, how does the repulsion between them change?
Initial repulsion is low and decreases as they approach .
Initial repulsion is high and decreases as they approach .
Initial repulsion is high and increases as they approach .
Initial repulsion is low and increases as they approach .
4. A positive charge of 5.0x10 ^ -5 C °is 0.040 m from a second positive charge of 2.0x10 ^ -6 C Calculate the force between the charges.
5.6x10^2 N
5.6x10^2 N
1.4X10^-2 N
2.3X10^1 N
(a) When the kinetic energy of an electron is transformed into potential energy is when it interacts with other electrons, decreasing its speed.
(b) The region of atoms that interact in bonds is electric fields of particles with negative charge.
(c) Initial repulsion is low and increases as they approach.
(d) The force between the charges is 562.5 N.
Kinetic theory of matter
This theory states that, the collision of particles (electrons) of matter is perfectly elastic. This implies that as the particles (electrons) collides with one another, kinetic energy is transferred from one electron to another.
ΔK.E = ΔP.E
Change in kinetic energy is equal to change in potential energy of the electrons.
Thus, when the kinetic energy of an electron is transformed into potential energy is when it interacts with other electrons, decreasing its speed. Decrease in speed implies decrease in kinetic energy and increase in potential energy.
Chemical bonds of moleculesChemical bond is formed from the transfer or sharing of electrons between atoms. (electrons between atoms implies negative charge to negative charge)
Thus, the region of atoms that interact in bonds is electric fields of particles with negative charge.
Coulomb's law
This law states that the force of attraction or repulsion between two charges is directly proportional to the product of the charges and inversely proportional to the distance between the charges.
[tex]F = \frac{kq_1q_2}{r^2}[/tex]
When the distance between the electrons are large, the repulsive force is low and the distance is small, the repulsive force is high.
Force between the chargesThe force between the charges is determined by applying Coulomb's law,
[tex]F = \frac{kq_1q_2}{r^2} \\\\F = \frac{9\times 10^9\times (5 \times 10^{-5}) \times (2\times 10^{-6})}{0.04^2} \\\\F = 562.5 \ N[/tex]
Learn more about Coulomb's law here: https://brainly.com/question/24743340
a hiker walks westward 2 meters and then eastward 7 meters. for this motion the distance moved is?
Answer:
d = 9 [m]
Explanation:
This is a problem where we must be clear about the concept of distance, which tells us that it is a measure of the space traveled on a trajectory.
Therefore:
d = 2 + 7
d = 9 [m]
The directions are not taken into account, as it is the sum of the displacements traveled, regardless of their directions.
Two spheres, 1.00 kg each, whose centers are 2.00 m apart, would have what gravitational force between them? A. 3.14 X 10-17 N
B. 1.67 X 10-11 N
C. 8.17 X 10-6N
D. 5.78 X 10-6 N
Answer: B
Explanation: the teacher just told us the answer
The gravitational force between the two spheres is [tex]1.67 \times 10^{-11} \ N[/tex].
The given parameters;
mass of each sphere, m = 1.00 kgdistance between their center mass, r = 2 mThe gravitational force between the two spheres is determined by applying Newton's law of universal gravitation as shown below;
[tex]F = \frac{Gm_1 m_2 }{r^2} \\\\[/tex]
where;
G is universal gravitation constant = 6.67 x 10⁻¹¹ N/m[tex]F = \frac{(6.67\times 10^{-11})\times (1\times 1)}{2^2} \\\\F = 1.67 \times 10^{-11} \ N[/tex]
Thus, the gravitational force between the two spheres is [tex]1.67 \times 10^{-11} \ N[/tex].
Learn more here:https://brainly.com/question/13590473
What is the condition required of the phase difference (in radians) between two waves with the same wavelength if these waves interfere constructively?
a. (2m +1)π where m= 0, +1, +2, etc.
b. mπ where m = 0, +1, +2, etc.
c. 2mπ where m = 0, +1, +2, etc.
d. (m+1)π where m = 0, +1, +2, etc.
Answer:
c.
Explanation:
In order to two waves with the same wavelength can interfere constructively, their crests and valleys must coincide in space, so the phase difference must be equal to an integer number of wavelengths, i.e. m *(2 π rad), where m= 0, +1, +2, etc.This is equal to the stated by the answer c) , so c) it's the right answer.PHYSICS! HELP ME PLEASE ASAP!
1.) If an ambulance passes you while you're walking your dog, a change in pitch is ____?
A.) not perceived by either the pedestrian or you
B.) perceived by the you
C.) perceived by the driver
2.) In the star wars movies, the soundtrack is very important. musicians and sound technicians spend weeks perfecting the noise of the light sabers, lasers, tie fighters and explosions. in real life, there would be no sound at all in space. Why?
A.) mechanical waves require a medium to travel
B.) sound is an electromagnetic wave
C.) mechanical waves do not require a medium to travel
D.) sound is a product of vibration
3.) what is a compression?
A.) region of zero pressure in a medium caused by a wave passing
B.)region of a high altitude in a medium caused by a passing wave
C.) region of a high pressure in a medium cause by a passing wave
D.) region of low pressure in a medium caused by a passing wave
Answer:
1B, 2B and 3C hope this helps
Explanation:
Suppose a uniform solid sphere of mass M and radius R rolls without slipping down an inclined plane starting from rest. The linear velocity of the sphere at the bottom of the incline depends on?
Answer:
None of the mass or the radius of the sphere
Explanation:
When a uniform solid sphere of any given mass, say M and any given radius, say R, rolls without slipping downwards an inclined plane that starts from rest. The linear velocity of the sphere at about the bottom of the inclined happens not to depend on either of its mass or that of the radius of its sphere.
A 1.2-kg object moving with a speed of 8.0 m/s collides perpendicularly with a wall and emerges with a speed of 6.0 m/s in the opposite direction. If the object is in contact with the wall for 2.0 ms, what is the magnitude of the average force on the object by the wall?
a. 9.8 kN.
b. 8.4 kN.
c. 7.7 kN.
d. 9.1 kN.
e. 1.2 kN.
Given that,
Mass of the object, m = 1.2 kg
Initial speed of the object, u = 8 m/s
Final speed of the object, v = -6 m/s (in opposite direction)
Time, t = 2 ms
To find,
The average force on the object by the wall.
Solution,
Let F be the force. Using Newton's second law of motion,
F = ma, a is acceleration
[tex]F=\dfrac{m(v-u)}{t}\\\\F=\dfrac{1.2\times ((-6)-8)}{2\times 10^{-3}}\\\\=8400\ N[/tex]
or
F = 8.4 N
So, the magnitude of average force in the object by the wall is 8.4 N.