How Does Surface Impact Affect Force on Falling Putty?

[fitchguy316]

A .45kg piece of putty is dropped from a height of 2.5m above a flat surface. When it hits the surface, the putty comes to a rest in .30s. What is the average force exerted on the putty by the surface?

V=d•t

F=m•a

a=v/t

 

[Doc Al]

impulse

Hint: Consider the impulse delivered by surface.