Answer:
From question (a) and (b) the pendulum motion is perpendicular to the force so the normal force will do no work and the tension in the string of the pendulum will not work
And 
so
c
An example will be a where a stone is attached to the end of a string and is made to move in a circular motion while keeping the other end of the string in a fixed position
d
A dog walking along a surface which has friction, here the frictional force would acting in the direction of the motion and this would do positive work
Explanation:
An object in motion stays in motion while an object at rest stays at rest.
Explanation:
Value of the cross-sectional area is as follows.
A = 
= 3.45 
The given data is as follows.
Allowable stress = 14,500 psi
Shear stress = 7100 psi
Now, we will calculate maximum load from allowable stress as follows.
= 
= 50025 lb
Now, maximum load from shear stress is as follows.
= 
= 48990 lb
Hence, 
will be calculated as follows.
= 48990 lb
Thus, we can conclude that the maximum permissible load is 48990 lb.
Try this option, the answers are marked with colour.
This behavior is called reflection.
Reflection is a change of in direction of the wave when it reaches another medium. Imagine a wave colliding with a glass in a tank of water.
During reflection, some of the initial energy of the wave is lost.
Waves always reflect with at same angle at which it approached the obstacle.
