Work is (force) times (distance). For Amy, you know both of them, and you can easily multiply them to find the amount of work. For Joe, the distance is zero, which should tell you all you need to know.
Answer:
.
Explanation:
If the mass of an object is 
and the velocity of that object is 
, the linear momentum of that object would be 
.
Assume that the initial velocity of the mass is positive (
.) However, the direction of the velocity is reversed after the impact. Thus, the sign of the new velocity of the object would be negative- the opposite of that of the initial velocity. The new velocity would be 
.
Thus, the change in the velocity of the mass would be:
.
The change in the linear momentum of the mass would be:
.
Thus, the magnitude of the change of the linear momentum would be 
.
I don't think so, because in order to produce an image, you need a surface behind the mirror. The light will hit the mirror, then it will bounce it back in your eyes and you see the image.
