Answer:
A: The acceleration is 7.7 m/s up the inclined plane.
B: It will take the block 0.36 seconds to move 0.5 meters up along the inclined plane
Explanation:
Let us work with variables and set

As shown in the attached free body diagram, we choose our coordinates such that the x-axis is parallel to the inclined plane and the y-axis is perpendicular. We do this because it greatly simplifies our calculations.
Part A:
From the free body diagram we see that the total force along the x-axis is:

Now the force of friction is
where
is the normal force and from the diagram it is 
Thus
Therefore,

Substituting the value for
we get:

Now acceleration is simply

The negative sign indicates that the acceleration is directed up the incline.
Part B:

Which can be rearranged to solve for t:

Substitute the value of
and
and we get:
which is our answer.
Notice that in using the formula to calculate time we used the positive value of
, because for this formula absolute value is needed.
Hey the answer to the question is
m = 0.40
<span>PE = m * g * h
PE = 60 * 9.8 * 4
PE = 2352 J
Power = E/t
Power = PE/t
Power = 2352/4.2
Power = 560 Watt</span>
Answer:
Explanation:
The horizontal component of force applied = 7.97 cos 26.2 = 7.15 N.
Vertical component in upward direction = 7.97 sin 26.2 = 3.52 N.
Since the body is moving with uniform velocity, friction force will equalize the external horizontal component = 7.15 N.
So frictional force = 7.15 N.
a) Work done by rope force per second = force in horizontal direction x displacement per second = 7.15 x 4.33 = 30.95 J
b) Increase in thermal energy per second will be due to negative work done by frictional force = work done by external force = 30.95 J.
c) Normal force acting downwards = weight - vertical component of external force = 4.36 x 9.8 - 3.52 = 39.21 N
coefficient of friction = friction force / normal force = 7.15 / 39.21 = 0.18