Answer:
kinetic friction may be greater than 400 N or smaller than 400 N
Explanation:
As we know that maximum value of static friction on the rough surface is known as limiting friction and the formula of this limiting friction is known as

now when object is sliding on the rough surface then the friction force on that surface is known as kinetic friction and the formula of kinetic friction is known as

now we know that

so here value of limiting static friction force is always more than kinetic friction
also we know that
initially when body is at rest then static friction value will lie from 0 N to maximum limiting friction
and hence kinetic friction may be greater than static friction or if the static friction is maximum limiting friction then kinetic friction is smaller than static friction
so kinetic friction may be greater than 400 N or smaller than 400 N
Thank you for posting your Physics question here. I hope the answer helps. Upon calculating the ramp with the horizontal the answer is 20.49 Deg. Below is the solution:
Y = 7 m.
<span>r = 20 m. </span>
<span>sinA = Y/r = 7/20 = 0.35. </span>
<span>A = 20.49 Deg.</span>
Both planets are similar in shape and have a rocky surface. Not sure about the phases though
Answer:
c. 981 watts

Explanation:
Given:
- horizontal speed of treadmill,

- weight carried,

- grade of the treadmill,

<u>Now the power can be given by:</u>

(where grade is the rise of the front edge per 100 m of the horizontal length)

Answer: Option (c) is the correct answer.
Explanation:
When a penny is dropped from a height of 20 meters then it will achieve an acceleration.
As acceleration is the rate of change in velocity of an object with respect to time. Therefore, the velocity does not remain constant.
Whereas mass of the penny will remain the same as it will not get affected when it falls. Also, there will be no change in direction of the penny as it is falling only in one direction.
The acceleration of penny is due to the force of gravity.
Thus, we can conclude that the force of gravity causes it to accelerate.