Answer:
True b and c
Explanation:
In an RLC circuit the impedance is
[tex]Z = \sqrt{[R^{2} + ( (wL)^{2} + (\frac{1}{wC})^{2} ] }[/tex]
examine the different phrases..
a) False. The maximum impedance is the value of the resistance
b) True. Resonance occurs when
(wL)² + (1 / wC)² = 0
w² = 1 / LC
c) True. In resonance the impedance is the resistive part and the power is maximum
d) False. In resonance the inductive and capacitive part cancel each other out
e) False. The impedance is always greater outside of resonance, but at the resonance point they are equal
What is food called when it enters the pharynx?
A.Bile
B.bolus
C. Food
D. Feces
Answer:
its food this was easy
Give reason:
a) In 'coin on card' experiment a smooth card is used.
Answer:
Please mark as brainliest!!
Explanation:
In coin card experiment smooth card is used so that the card can slide easily from glass.
Answer:
In coin card experiment smooth card is used so that the card can slide easily from glass.
the maximum intensity levels of a trumpet, trombone, and a bass drum, each at a distance of 3m are 94 dB, 107dB, and 113dB respectively. What is the intensity level of the three different instruments when played simultaneously, again at 3m?
Answer:
β = 114 db
Explanation:
The intensity of sound in decibles is
β = 10 log [tex]\frac{I}{I_{o}}[/tex]
in most cases Io is the hearing threshold 1 10-12 W / cm²
let's calculate the intensity of each instrument
I / I₀ = 10 (β / 10)
I = I₀ 10 (β / 10)
trumpet
I1 = 1 10⁻¹² 10 (94/10)
I1 = 2.51 10⁻³ / cm²
Thrombus
I2 = 1 10⁻¹² 10 (107/10)
I2 = 5.01 10-2 W / cm²
low
I3 =1 1-12 (113/10) W/cm²
I3 = 1,995 10-1 W / cm²
when we place the three instruments together their sounds reinforce
I_total = I₁ + I₂ + I₃
I_ttoal = 2.51 10-3 + 5.01 10-2 + 1.995 10-1
I_total = 0.00251 + 0.0501 + 0.1995
I_total = 0.25211 W / cm²
let's bring this amount to the SI system
β = 10 log (0.25211 / 1 10⁻¹²)
β = 114 db
A street bridge is 5.5m long if the linear expansion of steel is 0.00001 oc How much will it expand when temperatures is by 10oc? Give answer in Cm
Answer:
[tex]l_o=550.055\ cm[/tex]
Explanation:
Given that,
Length of a street bridge, l = 5.5 m
The coefficient of bridge, [tex]\alpha =0.00001 ^0 C[/tex]
We need to find how much will it expand when temperatures is by 10°C.
The change in length per unit original length is given by :
[tex]\dfrac{\Delta l}{l}=\alpha \Delta T\\\\\Delta l = l\alpha \Delta T\\\\=5.5\times 0.00001 \times 10\\\\\Delta l=0.00055\\\\(l_o-l)=0.00055\\\\l_o=0.00055+5.5\\\\=5.50055\ m\\\\l_o=550.055\ cm[/tex]
Hence, the length will expanded 550.055 cm.
An object at rest is suddenly broken apart into two fragments by an explosion. The first fragment (with mass m1) acquires twice the kinetic energy of the second one (with mass m2).
What is the ratio of their masses?
Answer:
m1 ÷ m2 = 1 ÷ 2
Explanation:
The ratio of their masses is as follows:
As it is given that the mass m1 is twice of mass m2
So the equation could be written as
[tex]\frac{1}{2} m1 v1 v1 = 2 \times \frac{1}{2} m2 v2 v2\\\\\frac{m1}{m2} = \frac{2 v2 v2}{v1 v1} ..........(1)[/tex]
Here we used the conservation of momentum
Prior to the explosion, the object is in rest so the momentum would be zero but after the explosion the total momentum would be m1v1 + m2v2, that is also zero.
So,
[tex]m1 v1 + m2 v2 = 0\\\\m1 v1 = - m2 v2\\\\\frac{m1}{m2} = \frac{- v2}{v1}[/tex]
Now squaring to the both sides
m1 m1 ÷ (m2 m2) = v2 v2 ÷ (v1 v1) ........(2 )
Solved both the equations
After solving it, the ratio is
m1 ÷ m2 = 1 ÷ 2
Use the following free body diagram to answer questions 8 and 9:
8. Calculate the net force acting on the cart.
A 0N
B. +60N
C -60N
D. +240 N
9. Calculate the cart's rate of acceleration
A +60 m/s
B. +8 m/s
C.-2m/s
D. +2 m/s
Answer:
8 is c and 9 is b it is shown though the practice as god lol
Question 8
The net force acting on the cart is:
F = 150 N - 90 N
F = 60 N
Question 9
By the Newtons second law:
F = ma
Solving for a:
a = F/m
a = 60 N / 30 kg
a = 2 m/s²
HELP ASAP!! i’ll mark you the brainliest!!
Answer:
yes
Explanation:
if an atom was a scale, in which the nucleus is the size of an apple the electron.....
Answer:
the nucleus is the size of an apple, approximately 5 cm of radius e, the atom has a radius of R = 5 cm 104 = 50000 cm = 50 km
Explanation:
In the Rutherford experiments it was proved that the atomic nucleus has the volume 10-4 the volume of the atom.
If we make a scale design in which the nucleus is the size of an apple, approximately 5 cm of radius e, the atom has a radius of R = 5 cm 104 = 50000 cm = 50 km
This shows that almost the entire volume of the atom is empty.
A stunt person jumps from the roof of a tall building, but no injury occurs because the person lands on a large, air-filled bag. Which one of the following best describes why no injury occurs?
A. The bag increases the amount of time during which the momentum is changing and reduces the average force on the person.
B. The bag increases the amount of time the force acts on the person and reduces the change in momentum.
C. The bag reduces the impulse to the person.
D. The bag provides the necessary force to stop the person.
E. The bag decreases the amount of time during which the momentum is changing and reduces the average force on the person.
Answer:
A stunt person jumps from the roof of a tall building, but no injury occurs because the person lands on a large, air-filled bag. Which one of the following best describes why no injury occurs?
The bag increases the amount of time during which the momentum is changing and reduces the average force on the person.
ANSWER: A
Answer:
A. The bag increases the amount of time during which the momentum is changing and reduces the average force on the person.
During stunts, people usually put an-air filled bag on the ground for safe landing and to prevent injuries.
Momentum is calculated by m* v where m is for mass and v is for velocity.
Force is directly proportional to momentum
F∝M
The bag in this scenario helps to increases the amount of time the force acts on the person. This implication means that there is a reduction in the change of momentum. Since Force and momentum have a directly proportional relationship then the Force taken to hit the floor is greatly reduced.
Read more on https://brainly.com/question/20362316
You're driving a bumper car at a circus at
18 m/sec, and you hit another car that's at
rest. If you end up going at 6.0 m/sec, what
is the final speed of the other car, given
that both cars have 100.0 kg mass, you
have 80.0 kg mass, and the other person
has a mass of 70.0 kg?
Answer:
PLEASE MARK AS BRAINLIEST!!
Explanation:
ANSWER IS IN THE IMG BELOW
This 200-kg horse ran the track at a speed of 5 m/s. What was the average kinetic energy?
Answer:
2500 JExplanation:
The average kinetic energy can be found by using the formula
[tex]k = \frac{1}{2} m {v}^{2} \\ [/tex]
m is the mass
v is the velocity
From the question we have
[tex]k = \frac{1}{2} \times 200 \times {5}^{2} \\ = 100 \times 25[/tex]
We have the final answer is
2500 JHope this helps you
The wavelength of a water wave is 54 m. It has a frequency of 0.03 Hz. What is the velocity of the wave?
Answer:
1.62 m/s
Explanation:
Wavelength of the water wave= 54 m
The frequency is 0.03 Hz
Therefore the velocity can be calculated as follows
Velocity= frequency × wavelength
= 0.03 × 54
= 1.62 m/s
Which would best help a student determine the net force acting on a rollercoaster car as it moves from one point on its track to another?
Answer:
you can show them a vid
Explanation:
identical spheres are dropped from a height of 100 m above the surfaces of Planet X and Planet Y. The speed of the spheres as a function of time is recorded for each planet in the graph
above. Which planet exerts the greater force of gravity on the sphere, and what evidence supports this conclusion?
A Planet X because its line has the greater area under it.
Planet X, because its line has the greater slope
Planet Y. because it falls for the smaller amount of time
Planet Y because the object's final speed is greater
Answer:
B. Planet X, because its line has the greater slope.
Explanation:
In a speed graph, acceleration is slope. A greater slope means a greater acceleration. According to Newton's 2nd law (F=mg), a greater acceleration means a greater force.
Planet X exerts the greater force of gravity on the sphere, because its line has the greater slope. Hence option B is correct.
What is Gravitational Force ?Gravitational force is force of attraction between two masses. Gravitational force(F) between two bodies is directly proportion to the product of masses(m₁,m₂) of two bodies and inversely proportional to square of distance(r) between them. mathematically it is written as,
F ∝ m₁.m₂
F ∝ 1/r²
F = G m₁,m₂÷r²
where G is gravitational constant, whose value is 6.6743 × 10⁻¹¹ m³ kg-1s⁻².
Force is expressed in Newton N in SI unit. its dimensions are [M¹L¹T⁻²].
This is analogous with coulomb's law which gives force between two charges.
if a planet has greater gravitational force(force of gravity), then body falls with greater speed as compare to other planet which is having less force of gravity. we can see in case of planet X there is greater speed as compare to plane Y in short time. Hence option B is correct.
To know more about Gravity :
https://brainly.com/question/31321801
#SPJ2.
A little girl pushes a 5.0 kg toy baby stroller at constant speed 7.0 m across the floor. She pushes on the handle with a force of 40 N at an angle of 30o with the horizontal. All parts are 4 points each.
Complete Question
1 a A little girl pushes a 5.0 kg toy baby stroller at constant speed 7.0 m across the floor. She pushes on the handle with a force of 40 N at an angle of 30o with the horizontal. How much work is done by the girl on the wagon?
1b A farmhand pushes 20 ㎏ bale of hay 4m across the floor of the barn if she exerts a horizontal force of 60 N on the hay, how much work is done? (5 pts)
All parts are 4 points each
Answer:
1a
[tex]W = 242.5 \ J[/tex]
1b
[tex]W = 240 \ J[/tex]
Explanation:
Considering question a
From the question we are told that
The mass of the toy baby stroller is [tex]m = 5.0 \ kg[/tex]
The distance covered is [tex]d = 7.0\ m[/tex]
The force the girl applies on the handle is [tex]F = 40 \ N[/tex]
The angle at which this force is applied is [tex]\theta = 30^o[/tex]
Generally the workdone is mathematically represented as
[tex]W = F_x * d[/tex]
Here [tex]F_x[/tex] is the force along the horizontal axis , this is mathematically represented as
[tex]F_x = F cos (\theta )[/tex]
=> [tex]F_x = 40 * cos(30 )[/tex]
=> [tex]F_x = 34.64 \ N[/tex]
So
[tex]W = 34.64 * 7[/tex]
=> [tex]W = 242.5 \ J[/tex]
Considering question b
From the question we are told that
The mass of the toy baby stroller is [tex]m = 20 \ kg[/tex]
The distance covered is [tex]d = 4 \ m[/tex]
The force the girl applies on the handle is [tex]F = 60 \ N[/tex]
Generally the workdone is mathematically represented as
[tex]W = F * d[/tex]
=> [tex]W = 60 * 4[/tex]
=> [tex]W = 240 \ J[/tex]
1. If a 4000 kg rocket reaches 7,000 m/s in 8 minutes after blastoff, what is its acceleration?
2. What force is being applied to the rocket?
3. What is the rocket's potential energy when it is 12 km off the ground?
(Hint - Change kilometers to meters)
4. If the rocket were to fall from the 12 km height, what would be its speed right before hitting the ground? (assume no air resistance)
+ answer all the questions plz
Answer:
I guess the Ans for second one is gravitational force
A ball of mass 4kg moving with a velocity of 20m/s collides with another ball of mass 15kg moving with a velocity of 15m/s in the same direction. Calculate the velocity of the 5kg ball if the collision is perfectly inelastic.
Answer:
velocity = 16.05 m/s
Explanation:
inelastic collision formula:
m1u1 + m2u2 = (m1 + m2)v
m1 = 4kg
u1 = 20m/s
m2 = 15kg
u2 = 15m/s
find v ?
m1u1 + m2u2 = (m1 + m2)v
(4×20) + (15×15) = (4+15)v
80 + 225 = 19v
305 = 19v
19v = 305
v = 305/19
v = 16.05 m/s
12 seconds after starting from rest a frewly falling cantaloupe has a speed of
Answer:
The cantaloupe has a speed of 117.6 m/s
Explanation:
Free Fall Motion
It occurs when an object falls under the sole influence of gravity. Any object that is being acted upon solely by the force of gravity is said to be in a state of free fall. Free-falling objects do not face air resistance.
If an object is dropped from rest in a free-falling motion, it falls with a constant acceleration called the acceleration of gravity, which value is [tex]g = 9.8 m/s^2[/tex].
The final velocity of a free-falling object after a time t is given by:
vf=g.t
The cantaloupe has been dropped from rest. We are required to find the speed after t=12 seconds.
Calculate the final speed:
vf=9.8 * 12 = 117.6 m/s
The cantaloupe has a speed of 117.6 m/s
1. A 3.8 kg scooter moves with a constant acceleration of 2.5 m/s”. Determine the net
applied force responsible for the acceleration.
Answer:
9.5 NExplanation:
The force acting on an object given it's mass and acceleration can be found by using the formula
force = mass × acceleration
From the question we have
force = 3.8 × 2.5
We have the final answer as
9.5 NHope this helps you
Explain how polarization of a cell increases the cell's internal resistance.
(2
2.
Answer:
Explanation: The chemical action that occurs in the cell while the current is flowing causes hydrogen bubbles to form on the surface of the anode. This action is called POLARIZATION. Some hydrogen bubbles rise to the surface of the electrolyte and escape into the air, some remain on the surface of the anode. If enough bubbles remain around the anode, the bubbles form a barrier that increases internal resistance. When the internal resistance of the cell increases, the output current is decreased and the voltage of the cell also decreases.
A cell that is heavily polarized has no useful output. There are several methods to prevent polarization or to depolarize the cell.
One method uses a vent on the cell to permit the hydrogen to escape into the air. A disadvantage of this method is that hydrogen is not available to reform into the electrolyte during recharging. This problem is solved by adding water to the electrolyte, such as in an automobile battery. A second method is to use material that is rich in oxygen, such as manganese dioxide, which supplies free oxygen to combine with the hydrogen and form water.
A third method is to use a material that will absorb the hydrogen, such as calcium. The calcium releases hydrogen during the charging process. All three methods remove enough hydrogen so that the cell is practically free from polarization.
LOCAL ACTION
When the external circuit is removed, the current ceases to flow, and, theoretically, all chemical action within the cell stops. However, commercial zinc contains many impurities, such as iron, carbon, lead, and arsenic. These impurities form many small electrical cells within the zinc electrode in which current flows between the zinc and its impurities. Thus, the chemical action continues even though the cell itself is not connected to a load.
Local action may be prevented by using pure zinc (which is not practical), by coating the zinc with mercury, or by adding a small percentage of mercury to the zinc during the manufacturing process. The treatment of the zinc with mercury is called amalgamating (mixing) the zinc. Since mercury is many times heavier than an equal volume of water, small particles of impurities weighing less than mercury will float to the surface of the mercury. The removal of these impurities from the zinc prevents local action. The mercury is not readily acted upon by the acid. When the cell is delivering current to a load, the mercury continues to act on the impurities in the zinc. This causes the impurities to leave the surface of the zinc electrode and float to the surface of the mercury. This process greatly increases the storage life of the cell.
One of the two rectangular components of a force is 20N and it makes an angle of 30
with the force. Find the magnitude of the other components.
Answer:
11.545NExplanation:
The the horizontal and vertical component be expressed as;
Fx = Fxos theta (horizontal compt)
Given Fx = 20N
theta = 30°
Get F:
20 = Fcos30
20 = 0.8660F
F = 20/0.8660
F = 23.09N
Get the magnitude of the other components. (vertical compt)
Fy = Fsin theta
Fy = 23.09sin30
Fy = 23.09(0.5)
Fy = 11.545N
Hence the magnitude of the other component is 11.545N
Need help ASAP plsss
Write 5-6 sentences about
:how do parachutes work ??
A ripcord system pulls a closing pin, which releases a spring-loaded pilot chute, and opens the container; from which the parachute comes out.
If a skydiver is unable to open her/his parachute, an automatic activation device will automatically open the parachute.
A parachute works by forcing air into the front of it and creating a structured 'wing' under which the canopy pilot can fly. Parachutes are controlled by pulling down on steering lines which change the shape of the wing, cause it to turn, or to increase or decrease its rate of descent.
Multiply.
(2x + 4)(x - 4)
Answer:
(2x + 4)(x - 4)=2x^2-4x-16
. A pendulum of length l = 9.8 m hangs in equilibrium and is then given velocity
v
=0.2
m/s at its lowest point. What is the amplitude of the subsequent oscillation?
Answer:
the amplitude of the sequence oscillation=
ASO = length × velocity
= 9.8 × 0.2 = 19.6
ASO = 19.6
You have to move your 100 N couch before a delivery company drops off your new one. Unfortunately your roommate is passed out on it. The coefficient of friction between the couch and floor is .43. It takes 250 N of force to get the couch moving. a) How much does your roommate weigh in Newton’s? b) After you get the couch moving it only takes 200 N to keep it moving at a constant speed, what is the coefficient of kinetic friction?
Answer:
a) Weight of Roommate = 481.4 N
b) μk = 0.34
Explanation:
a)
The force required to move the couch must be equal to the force of friction:
F = frictional force
F = μW
W = F/μ
where,
W = Total Weight of Couch and Roommate
F = Force Required start to move couch = 250 N
μ = coefficient of static friction between couch and floor = 0.43
Therefore,
[tex]W = \frac{250 N}{0.43}\\\\W = 581.4 N[/tex]
So, the total weight is given as:
W = Weight of Couch + Weight of Roommate
Weight of Roommate = W - Weight of Couch
Weight of Roommate = 581.4 N - 100 N
Weight of Roommate = 481.4 N
b)
Now, the force required to keep the couch moving can be given as equal to the kinetic friction force:
F = kinetic friction
F = μk*W
μk = F/W
where,
μk = coefficient of kinetic friction = ?
F = Force required to keep the couch moving = 200 N
Therefore,
μk = 200 N/581.4 N
μk = 0.34
Suppose that the separation between two speakers A and B is 6.60 m and the speakers are vibrating in-phase. They are playing identical 126-Hz tones and the speed of sound is 343 m/s. An observer is seated at a position directly facing speaker B in such a way that his line of sight extending to B is perpendicular to the imaginary line between A and B. What is the largest possible distance between speaker B and the observer, such that he observes destructive interference
Complete question
The diagram for this question is shown on the first uploaded image
Answer:
The largest possible distance is [tex]e = 15.33 \ m[/tex]
Explanation:
From the question we are told that
The separation between Speaker at position A and B is AB = 6.60 m
The frequency of the tune which the speaker are playing is [tex]f = 126 \ Hz[/tex]
The speed of sound is [tex]v = 343 \ m/s[/tex]
Generally the wavelength of the tune playing is mathematically represented as
[tex]\lambda = \frac{v}{f}[/tex]
=> [tex]\lambda = \frac{343}{ 126}[/tex]
=> [tex]\lambda = 2.72 \ m[/tex]
Let the observer be at position D
Generally the distance A and is mathematically evaluated using Pythagoras theorem as
[tex]AC = \sqrt{AB ^2 + BC^2}[/tex]
Let BC = e
So
[tex]AC = \sqrt{6.60 ^2 + e^2}[/tex]
Generally the path difference between the first and the second speaker from the observer point of view is mathematically represented as
[tex]P = AC - BC[/tex]
=> [tex]P = \sqrt{6.60 ^2 + e^2} - e[/tex]
Generally the condition for destructive interference is mathematically represented as
[tex]P = (2n - 1 )\frac{\lambda}{2}[/tex]
Here n is the order of the fringe which is one
=> [tex]\sqrt{6.60 ^2 + e^2} - e = (2 * 1 - 1 )\frac{2.72}{2}[/tex]
=> [tex]\sqrt{6.60 ^2 + e^2} - e = 1.36[/tex]
=> [tex]6.60 ^2 + e^2 =( 1.36 +e)^2[/tex]
=> [tex]6.60 ^2 + e^2 =1.8496 + 2.72e +e^2[/tex]
=> [tex]e = 15.33 \ m[/tex]
A thyristor (SCR) is a
Answer:
A thyristor (/θaɪˈrɪstər/) is a solid-state semiconductor device with four layers of alternating P- and N-type materials. It acts exclusively as a bistable switch, conducting when the gate receives a current trigger, and continuing to conduct until the voltage across the device is reversed biased, or until the voltage is removed (by some other means).
Explanation:
Correct me if im wrong
100 points!! word bank!
⬇️Article⬇️
Have you ever cut an apple in half and looked at the layers inside? When you cut something in half, the resulting view is called a cross section. When you look at the cross section of an apple, you see several layers: the skin, the pulp, the core, and the seeds. Much like the apple, Earth is made up of layers, too. If you could look at a cross section of our planet, you would see the crust. the mantle, the outer core, and the inner core. If Earth were an apple, the crust would be the apple’s skin. The mantle would be the apple’s pulp, making up most of the inside. Earth also has a central core, similar to an apple’s core, though Earth’s core does not contain any seeds! Of course, scientists cannot cut the whole planet in half to see a cross section the way you can with an apple. How do you think scientists know about Earth’s internal layers?
Scientists divide Earth’s interior into distinct layers.
Scientists can distinguish different layers in Earth depending on the properties used to identify each layer. For example, scientists identify the crust, mantle, and core based on each layer’s basic chemical composition. In other words, the crust, mantle, and core are each made up of different chemical elements. The crust and mantle are composed primarily of the elements oxygen and silicon. These are known as silicates. Silicates of the mantle contain heavier elements. This makes them denser than those found in the crust. The core is composed of the densest materials, primarily iron and nickel. Earth’s layers can also be identified by using each layer’s physical state of matter. The crust and the uppermost part of the mantle, together, make up a layer called the lithosphere. The lithosphere is the cool, rigid, outermost layer of Earth. The lithosphere is in the solid
In a typical silicate molecule, a silicon atom is bonded to four oxygen atoms. The atoms form a crystal structure.
Scientists use models to represent the different layers of Earth’s interior.
When constructing a model of the layers of Earth, scientists need to consider the chemical composition, state of matter, and thickness of each layer. Just like the skin of an apple, Earth’s crust is very thin compared to the other layers. It is about 25–70 km thick beneath the continents. Under the oceans, the crust is only about 5–7 km thick; however, it is much denser. The mantle is much thicker than the crust is, taking up most of Earth’s volume. The mantle begins directly beneath Earth’s crust. It reaches all the way to the outer core, about 2,900 km below the planet’s surface. In other words, Earth is about 1% crust, 83% mantle, and 16% core.
The crust and uppermost mantle are solid. The rest of the mantle is solid with plasticity. The core is made of very dense iron and nickel. The outer core is liquid, because it is hot enough to melt the iron and nickel. The inner core is solid. Even though it is as hot as the outer core, there is so much pressure at the very center of Earth that the iron and nickel stay in a solid state.
Looking to the Future: Exploring Earth’s Interior
Despite what you may have read in stories or seen in movies, scientists have never journeyed to the center of Earth. In fact, scientists have never made it through Earth’s crust! However, this has not stopped them from trying. The crust at the bottom of the oceans is much thinner than the crust of the continents. Therefore, drilling through the oceanic crust is the best chance that scientists have to make it to the mantle.
Answer:
Except in the crust, the interior of the Earth cannot be studied by drilling holes to take samples. Instead, scientists map the interior by watching how seismic waves from earthquakes are bent, reflected, sped up, or delayed by the various layers.
Explanation:
a machine
of efficiency of 70% is used to raise
a body of
mass 80 kg through
a vertical distance of 3m in
40 seconds. Calculate the power input. (Take g = 10 m/s²)
Answer:
Power_input = 85.71 [W]
Explanation:
To be able to solve this problem we must first find the work done. Work is defined as the product of force by distance.
[tex]W = F*d[/tex]
where:
W = work [J] (units of Joules)
F = force [N] (units of Newton)
d = distance [m]
We need to bear in mind that the force can be calculated by multiplying the mass by the gravity acceleration.
Now replacing:
[tex]W = (80*10)*3\\W = 2400 [J][/tex]
Power is defined as the work done over a certain time. In this way by means of the following formula, we can calculate the required power.
[tex]P=\frac{W}{t}[/tex]
where:
P = power [W] (units of watts)
W = work [J]
t = time = 40 [s]
[tex]P = 2400/40\\P = 60 [W][/tex]
The calculated power is the required power. Now as we have the efficiency of the machine, we can calculate the power that is introduced, to be able to do that work.
[tex]Effic=0.7\\Effic=P_{required}/P_{introduced}\\P_{introduced}=60/0.7\\P_{introduced}=85.71[W][/tex]
what type of friction present when you wrench on a car?
Answer:Rolling friction is friction that acts on objects when they are rolling over a surface. Rolling friction is much weaker than sliding friction or static friction. This explains why most forms of ground transportation use wheels, including bicycles, cars, 4-wheelers, roller skates, scooters, and skateboards.
Explanation: