Question

answer the give reason given below .please answer this

Answer 1

a) displacement of wall is 0.

b) hammer is raised to a height so to gain potential energy and when it comes down it converts into kinetic energy and drives a nail into the wood .

c)horse , as mass of horse is more than dog .

1/2 mv^2

d) displacement by the student is 0 so work done is also 0.

Answer 2

A) because no displacement is there in pushing against the wall