Answer:
Average speed is 5 m/s
Explanation:
The initial speed = 0 m/s (since the runner starts from rest)
Final speed = 10 m/s
time interval = 2 sec
average speed = ?
The speed is assumed to change at a constant rate
Average speed = (final speed + initial speed)/2
==> (10 + 0)/2 = 10/2 = 5 m/s
How could you record the number 4000 and report 2 significant figures?
Explanation:
Write in scientific notation.
4000 = 4.0×10³
Which of the following does a microscope use to produce an image?
a) reflection
b) refraction
c) total internal reflection
d) two of A, B, and C
e) all of A, B, and C
Answer:
All of a,b, and c hope this helps
A stone is thrown directly upward with an initial speed of 4 m/s from a height of 20 m. After what time interval does the stone strike the ground
Given :
( Let , take upward direction +ve and downward direction -ve )
Initial speed of stone , u = 4 m/s .
Height , h = 20 m .
To Find : Time taken to reach ground .
Solution :
We know , by equation of motion .
Displacement is given by :
[tex]h=h_o+ut+\dfrac{gt^2}{2}\\\\0=20+4t-2t^2\\\\t^2-2t-10=0[/tex] ( Here , g = acceleration due to gravity = [tex]-9.8\ m/s^2[/tex] .)
Solving above equation , we get :
t = 4.32 s .
Hence , this is the required solution .
a ball of mass 100g moving at a velocity of 100m/s collides with another ball of mass 400g moving at 50m/s in same direction, if they stick together calculate the velocity and loss of energy
Answer:
Velocity of the two balls after collision: [tex]60\; \rm m \cdot s^{-1}[/tex].
[tex]100\; \rm J[/tex] of kinetic energy would be lost.
Explanation:
VelocityBecause the question asked about energy, convert all units to standard units to keep the calculation simple:
Mass of the first ball: [tex]100\; \rm g = 0.1\; \rm kg[/tex].Mass of the second ball: [tex]400\; \rm g = 0.4 \; \rm kg[/tex].The two balls stick to each other after the collision. In other words, this collision is a perfectly inelastic collision. Kinetic energy will not be conserved. The velocity of the two balls after the collision can only be found using the conservation of momentum.
Assume that the system of the two balls is isolated. Thus, the sum of the momentum of the two balls will stay the same before and after the collision.
The momentum of an object of mass [tex]m[/tex] and velocity [tex]v[/tex] is: [tex]p = m \cdot v[/tex].
Momentum of the two balls before collision:
First ball: [tex]p = m \cdot v = 0.1\; \rm kg \times 100\; \rm m \cdot s^{-1} = 10\; \rm kg \cdot m \cdot s^{-1}[/tex].Second ball: [tex]p = m \cdot v = 0.4\; \rm kg \times 50\; \rm m \cdot s^{-1} = 20\; \rm kg \cdot m \cdot s^{-1}[/tex].Sum: [tex]10\; \rm kg \cdot m \cdot s^{-1} + 20 \; \rm kg \cdot m \cdot s^{-1} = 30 \; \rm kg \cdot m \cdot s^{-1}[/tex] given that the two balls are moving in the same direction.Based on the assumptions, the sum of the momentum of the two balls after collision should also be [tex]30\; \rm kg \cdot m \cdot s^{-1}[/tex]. The mass of the two balls, combined, is [tex]0.1\; \rm kg + 0.4\; \rm kg = 0.5\; \rm kg[/tex]. Let the velocity of the two balls after the collision [tex]v\; \rm m \cdot s^{-1}[/tex]. (There's only one velocity because the collision had sticked the two balls to each other.)
Momentum after the collision from [tex]p = m \cdot v[/tex]: [tex](0.5\, v)\; \rm kg \cdot m \cdot s^{-1[/tex].Momentum after the collision from the conservation of momentum: [tex]30\; \rm kg \cdot m \cdot s^{-1}[/tex].These two values are supposed to describe the same quantity: the sum of the momentum of the two balls after the collision. They should be equal to each other. That gives the equation about [tex]v[/tex]:
[tex]0.5\, v = 30[/tex].
[tex]v = 60[/tex].
In other words, the velocity of the two balls right after the collision should be [tex]60\; \rm m \cdot s^{-1}[/tex].
Kinetic EnergyThe kinetic energy of an object of mass [tex]m[/tex] and velocity [tex]v[/tex] is [tex]\displaystyle \frac{1}{2}\, m \cdot v^{2}[/tex].
Kinetic energy before the collision:
First ball: [tex]\displaystyle \frac{1}{2} \, m \cdot v^2 = \frac{1}{2}\times 0.1\; \rm kg \times \left(100\; \rm m \cdot s^{-1}\right)^{2} = 500\; \rm J[/tex].Second ball: [tex]\displaystyle \frac{1}{2} \, m \cdot v^2 = \frac{1}{2}\times 0.4\; \rm kg \times \left(50\; \rm m \cdot s^{-1}\right)^{2} = 500\; \rm J[/tex].Sum: [tex]500\; \rm J + 500\; \rm J = 1000\; \rm J[/tex].The two balls stick to each other after the collision. Therefore, consider them as a single object when calculating the sum of their kinetic energies.
Mass of the two balls, combined: [tex]0.5\; \rm kg[/tex].Velocity of the two balls right after the collision: [tex]60\; \rm m\cdot s^{-1}[/tex].Sum of the kinetic energies of the two balls right after the collision:
[tex]\displaystyle \frac{1}{2} \, m \cdot v^{2} = \frac{1}{2}\times 0.5\; \rm kg \times \left(60\; \rm m \cdot s^{-1}\right)^2 = 900\; \rm J[/tex].
Therefore, [tex]1000\; \rm J - 900\; \rm J = 100\; \rm J[/tex] of kinetic energy would be lost during this collision.
You throw a 20-N rock vertically into the air from ground level. You observe that when it is a height 14.8m above the ground, it is traveling at a speed of 25.0 m/s upward.
A) Use the work-energy theorem to find its speed just as it left the ground. What is it?
B) Use the work-energy theorem to find its maximum height. What is it?
Answer:
30.25 m/s
46.68 m
Explanation:
Work Energy theorem states that
W = ½mv2² - ½mv1²
W = ½m(v2² - v1²)
Net work done by the force = -mgd
Net work done = -m * 9.8 * 14.8
Net work done = -145m
Using the work energy theorem
-145m = ½m(v2² - v1²)
-145m = ½ * m(25² - v1²)
-290m = 625m - v1²m
v1² = 625 + 290
v1² = 915
v1 = √915 = 30.25 m/s
B
-mgd = ½m(v2² - v1²), where v2 = 0, so
-mgd = ½mv1²
Making d the subject of the formula, we have
d = -½mv1²/mg
d = v1²/2g
d = 915/ 2 * 9.8
d = 915 / 19.6
d = 46.68 m
Which of the following situations describes static friction? a. A heavy crate standing on a rough patch of mud and is being pushed by two workers, but they cannot get it to move b. A large piano resting on a sheet of ice is being pushed by a child, but the child is not strong enough to get it to move
Answer:
A.
Explanation:
The answer is A because the weight of the crate is sitting on something rough. The roughness is going to resist anything that tries to move against it because the force being exerted by the 2 workers is not strong enough to get the crate to move out of its place on the mud since it's static.
The answer can't be B because ice is smooth and doesn't have any friction, the little girl can't move it because it's to heavy for her to move, not because there's friction acting against it.
The resistance one encounters when attempting to move a stationary object over a surface without also moving their bodies in relation to the surface is known as static friction. Thus, option A is correct.
What the best situations describes static friction?An object cannot move down the path due to a force known as static friction. Two materials sliding over one another causes this friction. Conflict can be found everywhere around us. Consider how the ground is in contact with our feet when we walk.
When there is no relative motion between the object and the surface, a body is subjected to the effects of static friction. As a result, it can still act when the body is moving, but there shouldn't be any relative motion.
Therefore, Static friction slows the car down if the tire is moving so smoothly that the ground-contact surface is never slipping. Kinetic friction will cause the wheels to slow down if they are locked and sliding.
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Use the graph to compare the three local teams that play in the summer basketball league. Predict which local team would have the best finish in a basketball tournament. Explain your answer.
Answer:
Sample Response: The Jaguars would probably have the best finish in a basketball tournament because they have won the most games every season.
Explanation:
Answer:
Sample Response: The Jaguars would probably have the best finish in a basketball tournament because they have won the most games every season.
Explanation:
As shown on the graph, the Jaguars had the most wins each season compared to the Wolves and the Hawks. In conclusion, you can predict that the Jaguars would probably have the best finish in a basketball tournament.
What does CWT stand for?
hundredweight cwt is a standard unit of weight or mass used in certain commodities trading contracts.
Answer:
hundredweight
Explanation:
average wavelength of radio waves
Answer:
Radio waves have frequencies as high as 300 gigahertz(GHz)to as low as 30 hertz(Hz).At 300 GHz the corresponding wavelength is 1mm and at 30Hz is 10,000 km
The average wavelength of radio waves ranges from roughly two millimeters to more than 150 kilometers. The wavelengths of radio waves are the longest in the electromagnetic spectrum
What is Wavelength?It can be understood in terms of the distance between any two similar successive points across any wave for example wavelength can be calculated by measuring the distance between any two successive crests.
It is the total length of the wave for which it completes one cycle.
The wavelength is inversely proportional to the frequency of the wave as from the following relation.
C = νλ
They also have the lowest frequencies, ranging from around 4,000 cycles per second, or 3 kilohertz, to roughly 280 billion hertz, or 280 gigahertz.
The wavelengths of radio waves are the longest in the electromagnetic spectrum, ranging from roughly two millimeters to more than 150 kilometers.
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A 54 kg pig runs at a speed of 1.0
What is the pig's kinetic energy?
Round answer to two significant digits.
Answer:
27 Joules.
Explanation:
use the formula for kinetic energy:
KE = 1/2mv^2
A 54 kg pig runs at a speed of 1.0 m/s.
What is the pig’s kinetic energy?
Answer: 27 J
How much would it cost to cover the entire land area of the U.S. in dollar bills?
How much would it take to cover the entire land area of the U.S. in dollar bills?
The contiguous United States can be approximated as a rectangle that measures 1000 x 3000 miles, while Alaska has about 1/5 of the area of the contiguous U.S. Ignore Hawaii for this calculation. Also note that the dollar bill measures roughly 6.5cm x 15.5cm.
How much would it cost to cover the entire land area of the United States?
*Round your answer to one significant figure*
Answer:
$900 trillion
Explanation:
If Alaska is 20% of the contiguous US, then the approximate area of interest is ...
1200 miles × 3000 miles = 3.6×10^6 square miles.
The size of a dollar bill is about ...
(6.5 cm)·(15.5 cm) = 100.75 cm^2
One mile is 160,934.4 cm, so 1 square mile is about ...
1 mi^2 = (160,934.4 cm)^2 ≈ 2.59·10^10 cm^2
The number of dollars of interest is then ...
(3.6 · 10^6 mi^2)(2.59 · 10^10 cm^2)/(100.75 cm^2) ≈ 9.3·10^14
≈ 930 × 10^12 . . . dollars
It would cost about 900 trillion dollars to cover the land area of the US in $1 bills.
Jennifer has taught her pet rat to run a maze. She thinks that the rat will
go faster if she puts its favorite treat at the end. She has the rat run the
maze ten times with the favorite treat and ten times with a regular food
pellet. She uses a stopwatch to measure how long it takes for the rat to get
to the reward.
O Replication
O Repetition
Please give an example of a scenario with distance and displacement.
Answer:
distance means the length of any thing that have one starting point mad ending point
displacement means the short distance that move by an object due to help of any force
Answer:
there is examples and defination for distance and displacement
If the maximum acceleration that is tolerable for passengers in a subway train is 1.39 m/s2 and subway stations are located 780 m apart, what is the maximum speed a subway train can attain between stations
Answer:
The maximum speed a subway train can attain between stations is 32.93 m/s.
Explanation:
Given;
maximum tolerable acceleration = 1.39 m/s²
distance between subway train, d = 780 m
The distance available to accelerate between stations = ¹/₂ x 780 m = 390 m
Apply the following kinematic equation to determine the maximum speed;
v² = u² + 2ad
v² = 0 + 2ad
v² = 2(1.39)(390)
v² = 1084.2
v = √1084.2
v = 32.93 m/s
Therefore, the maximum speed a subway train can attain between stations is 32.93 m/s.
A 12-V DC automobile head lamp is to be used on a fishing boat with a 24-V power system. The head lamp is rated at 50 W. A resistor is to be connected in series with the lamp to permit it to operate on 24 V. What should be the resistance and power rating of the resistor?
Answer:
The resistance is [tex]R = 2.88 \ \Omega[/tex]
Explanation:
From the question we are told that
The voltage rating of the headlamp is [tex]V_1 = 12 \ V[/tex]
The voltage of the power system is [tex]p = 24 \ V[/tex]
The power rating of the headlamp is [tex]P = 50 W[/tex]
Generally the power which the resistor dissipates is mathematically represented as
[tex]P = V_L * I[/tex]
=> [tex]50 = 12 * I[/tex]
=> [tex]I = 4.1667 \ A[/tex]
Generally the resistance is
[tex]R = \frac{V_1 }{I}[/tex]
[tex]R = \frac{12 }{4.1667}[/tex]
[tex]R = 2.88 \ \Omega[/tex]
A bull pulls a plough with constant force of 200N along a field through a distance of 10m in 10s. What is the power of bull?
Answer:
we have to find out the work done in order to find the power since power is the amount of joules spent every second
work done by the bull = Force * Displacement
work done = 200 N * 10 m
work done = 2000 Nm or 2000 j
since we know that the bull spent the 2000 j in 10 seconds,
we will find the amount of energy spent in a second:
power = work done / time
power = 2000 / 10
power = 200 W
a brainly will be appreciated
Answer:
200W
Explanation:
as power = work/time
= force * distance /time
= 200 * 10/ 10
==200W
A 15.0 nC point charge is 15 m from a second point charge, and the electric force on one of them due to the other is 5.0 N. What is the magnitude of t
Answer:
t = 125 C
Explanation:
The force on a charge due to other charge is given by Coulomb's Law, as follows:
F = kq₁q₂/r²
where,
F = Electric Force = 5 N
k = Coulomb Constant = 9 x 10⁹ N.m²/C²
q₁ = magnitude of first charge = 15 nC = 1.5 x 10⁻⁸ C
q₂ = Magnitude of 2nd Charge = t = ?
r = distance between charges = 15 m
Therefore,
5 N = (9 x 10⁹ N.m²/C²)(1.5 x 10⁻⁸ C)t/(15 m)²
t = (5 N)/(0.04 N/C)
t = 125 C
Which shows the temperatures of three substances, in order, from greatest to least?
ОООО
water vapor, ice, water
ice, water, water vapor
water, water vapor, ice
water vapor, water, ice
Answer:
Hey !.
I think the answer will be water vapour,ice ,water.
Answer:
water vapor, water, ice
Hope this answer correct ✌️
Timmy drove 2/5 of a journey at an average speed of 20 mph.
He drove the remaining 60 miles at another speed. If the
average speed for the whole journey was 25 mph, what's the
amount of time for the whole journey?
Answer:
4hr
Explanation:
The total time Timmy spent in the whole journey is 4 hours.
The given parameters;
average speed of Timmy for [tex]\frac{2}{5}[/tex] of the journey = 20 mphthe remaining fraction of the journey = 60 milesaverage speed of the entire journey = 25 mphThe total distance of the journey is calculated as follows;
[tex]( 1 - \frac{2}{5} ) \times total = 60 \ miles\\\\\frac{3}{5} \times total = 60\\\\total = \frac{60 \times 5}{3} \\\\total = 100 \ miles[/tex]
The amount of time for the whole journey is calculated as follows;
[tex]average \ speed = \frac{total \ distance}{total \ time} \\\\total \ time = \frac{100 \ miles }{25 \ mph} \\\\total \ time = 4 \ hours[/tex]
Thus, the total time Timmy spent in the whole journey is 4 hours.
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You fly east in an airplane for 100 km. You then turn left 60 degrees and fly 200 km. In what direction are you from the starting point
Answer:
North east
Explanation:
r_1 = 100 i
r_2 = 200 (cos60i + sin60j) = 100i + 173.2j
By vector addition
r = r_1 + r_2 = 200i + 173.2j
Distance (Or magnitude) = sqrt(200^2 + 173.2^2) = 264 km
Direction from the starting point is north of east.
If the voltage across the plates is increasing at the rate of 220 V/s, what is the displacement current in the capacitor
Complete Question
A parallel-plate capacitor has square plates 20 cm on a side and 0.50 cm apart. If the voltage across the plates is increasing at the rate of 220 V/s, what is the displacement current in the capacitor?
Answer:
The value is [tex]I = 1.416*10^{-8} \ A[/tex]
Explanation:
From the question we are told that
The length and breath of the square plate is [tex]l = b = 20 \ cm = 0.2 \ m[/tex]
The distance of separation between each plate is [tex]k = 0.50 \ cm = 0.005 \ m[/tex]
The rate of voltage increase is [tex]\frac{dV}{dt} = 200 \ V/s[/tex]
Generally the charge on the plate is mathematically represented as
[tex]Q = CV[/tex]
Now C is the capacitance of the capacitor which is mathematically represented as
[tex]C = \frac{\epsilon_o * A}{k}[/tex]
Here A is the cross-sectional area which is mathematically represented as
[tex]A = l^2[/tex]
=> [tex]A = 0.2^2[/tex]
=> [tex]A = 0.04 \ m^2[/tex]
So
[tex]C = \frac{8.85 *10^{-12} * 0.04}{0.005}[/tex]
[tex]C = 7.08*10^{-11} \ F[/tex]
Now the change of the charge flowing through the plates with time is mathematically represented as
[tex]\frac{d Q}{dt} = C \frac{dV}{dt}[/tex]
So
[tex]\frac{d Q}{dt} = 7.08 *10^{-11} * 200[/tex]
[tex]\frac{d Q}{dt} = 1.416*10^{-8}[/tex]
Generally [tex]\frac{d Q}{dt} = \ current \ i.e \ I[/tex]
So
[tex]I = 1.416*10^{-8} \ A[/tex]
The pressure gauge on a tank registers the gauge pressure, which is the difference between the interior pressure and exterior pressure. When the tank is full of oxygen (O2), it contains 11.0 kg of the gas at a gauge pressure of 35.0 atm. Determine the mass of oxygen that has been withdrawn from the tank when the pressure reading is 19.4 atm. Assume the temperature of the tank remains constant.
Answer:
mass of oxygen that has been withdrawn from the tank = 4.77 kg
Explanation:
We are given;
Initial mass of oxygen gas;m1 = 11 kg
Initial gauge pressure;p'1 = 35 atm
Final gauge pressue;p'2 = 19.4 atm
Now, for thia question we cannot use gauge pressure but absolute pressures.
Thus, formula for absolute pressure = gauge pressure + external atmospheric pressure.
External atmospheric pressure = 1 atm.
Thus;
P1 = 35 + 1 = 36 atm
P2 = 19.4 + 1 = 20.4 atm
Now, formula for ideal gas equation is;
PV = nRT = (m/M)RT
Where;
m is mass of gas
M is molar mass of gas
R is gas constant
T is temperature
Thus, for state 1,we have;
P1 × V1 = (m1/M)RT1 - - - (eq 1)
For state 2,we have;
P2 × V2 = (m2/M)RT2 - - - - - (eq 2)
Divide equation 1 by equation 2 to give;
(P1 × V1)/(P2 × V2) = (m1 × T1)/(m2 × T2)
The gas remains confined in the tank, thus, V1 = V2
Also, the temperature is constant, thus T1 = T2.
Thus, V1 & V2 and also T1 & T2 will cancel out to give;
P1/P2 = m1/m2
Since we are looking for the mass of oxygen( Δm) that has been with withdrawn from the tank, we have to rewrite the equation to accommodate Δm. Now, Δm is simply m1 - m2
Thus,
From P1/P2 = m1/m2, we have;
P1/P2 = m1/(-(m1 - m2) + m1)
This gives;
P1/P2 = m1/(m1 - Δm)
Cross multiply to get;
(m1 - Δm)(P1/P2) = m1
Cross multiply to get;
m1 - Δm = (P2/P1)m1
Δm = m1 - (P2/P1)m1
Δm = m1(1 - (P2/P1))
Plugging in the relevant values to get;
Δm = 11(1 - (20.4/36))
Δm = 4.77 kg
Based on your answer to the previous question (bullet embeds in block), what type of collision would you classify the bullet-block impact?
Answer:
An inelastic collision.
Explanation:
When a bullet impacts on the block, and is embedded in the block, the bullet-block system moves away together, with a single velocity together. This is called "an inelastic collision"
In this type of collision, only the momentum of the system is conserved.
Two forces 5N and 10N are acting at "O" and "P" respectively on a uniform rod of length 100 cm suspended at the position of center of gravity 50cm mark as shown in figure .
Answer:
Option C. 75 cm
Explanation:
To obtain the position of P, let us calculate the value of y as shown in the attached photo.
The value of y can be obtained as follow:
Anticlockwise moment = clockwise moment
Anticlockwise moment = 5 × 50
Anticlockwise moment = 250
Clockwise moment = y × 10
Anticlockwise moment = clockwise moment
250 = y × 10
Divide both side by 10
y = 250/10
y = 25 cm
Finally, we shall obtain the value of P as follow:
Since P lies after the pivot (i.e 50 cm), therefore,
P = 50 + y
y = 25
P = 50 + 25
P = 75 cm
Therefore, the position of P on the metre rod is 75 cm
similarity of gravity and electromagnetic force
Answer:
Gravity is an attractive force as well as electromagnetic, but electromagnetic attracts and repels.
Explanation:
5. What kind of mirror would you use if you needed to start a fire using a mirror? Why? At what position would you place the kindling from the mirror?
Answer:
Concave mirror
The kindling should be positioned at the focus point of the mirror
Explanation:
A concave mirror should be used, because it forms a real image, and focuses the image of an incident ray coming from a distant source on a single point. These mirrors are called "converging mirrors" because they tend to collect light that falls on them, refocusing parallel incoming rays toward a focus, and are sometimes used to collect light from a large area and focus it into a small spot, as in concentrated solar power.
Describe a sound wave. Discuss what determines pitch and volume.
Answer:
The amplitude of a sound wave is a reflection of how much energy is carried, which contributes to the intensity of the sound. Intensity is measured in decibels and is perceived as sound volume. Thus, the volume is proportional to the amplitude of the sound wave. The frequency of a sound wave is perceived as pitch.
Explanation:
The amount of energy carried by a sound wave is reflected in its amplitude, which affects the sound's intensity. The perception of intensity as sound loudness is expressed in decibels. Hence, the relationship between the volume and the sound wave's amplitude is clear. Pitch is the perceived frequency of a sound wave.
What is wave ?Wave is is a disturbance in a medium that carries energy as well as momentum . wave is characterized by amplitude, wavelength and phase. Amplitude is the greatest distance that the particles are vibrating. especially a sound or radio wave, moves up and down. Amplitude is a measure of loudness of a sound wave. More amplitude means more loud is the sound wave.
Wavelength is the distance between two points on the wave which are in same phase.
Phase is the position of a wave at a point at time t on a waveform.
There are two types of the wave longitudinal wave and transverse wave.
Longitudinal wave : in which, vibration of the medium (particle) is parallel to propagation of the wave. Sound wave is a longitudinal wave.
Transverse wave : in which, vibration of the medium (particle) is perpendicular to propagation of the wave. Light wave is a Transverse wave.
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what was the average speed in km/h of a car that travels 490.0 km in 4.2 h?
Answer:
116.67 km/h
Explanation:
avarge speed = total distance / total time
Answer: 490 / 4.2 = 116.67 km/h
for an ideal gas, a plot of In P versus 1 / T (in Kelvin) yields a straight line with a slope equal to
three equal charges are fixed at the three corners of a rectangle what is the force on the top left charge from the bottom left
Answer:
hello your question is incomplete attached below is the missing parts and the detailed solution of the problem
answer : [tex]\frac{1}{4\pi e_{0} } * \frac{q^2}{h^2} i_{y}[/tex] ( D )
Explanation:
The force on the top left charge from the bottom left can be determined applying the equations/expression as represented in the detailed solution
option D was chosen because it accurately represents the force on the top left charge( positive y axis ) from the bottom left