The work done by the friction force to stop the player is equal to his loss of kinetic energy:

The work done by the friction force is the magnitude of the force

times the distance covered by the player, d:

The loss in kinetic energy is simply equal to the initial kinetic energy of the player, since the final kinetic energy is zero (the player comes to rest):

Substituting into the first equation, we get:

from which we find d, the distance covered by the player:
Answer:

Explanation:
The expression which represent the first diffraction minima by a circular aperture is given by
--------eqn 1
The angle through which the first minima is diffracted is given by
---------eqn 2
As
is very small so we can write 
So from eqn 1 and eqn 2 we can write
--------eqn 3
Here
is the position of first maxima D is the distance of screen from the circular aperture d is the diameter of aperture
It is given that diameter of circular aperture is 14.7 cm so 
Now putting all these value in eqn 3


Answer:
Zero
Explanation:
According to Newton's second law, the net force acting on an object is equal to the product between the object's mass and its acceleration:
F = ma
For the hockey puck, there are no forces acting on it during its motion, since ice friction and air resistance are negligible. This means that the net force is zero:
F = 0
But this means that the acceleration is also zero:
a = 0
So the hockey puck is moving already at constant velocity. Therefore, there is no need for additional forces.
The slope of a velocity time graph gives the value of acceleration of car. The slope of car X at t=40 s is less than the slope of car Y. Therefore, the acceleration of car X is less than the acceleration of car Y at t=40 s.