- #1

A 1.5 kg block is initially at rest on a horizontal frictionless surface when a horizontal force in the pos direction of an x axis is applied to the block. The force is given by F(x) = (2.5 - x^2)i N, where x is in m and the initial position of the block is x = 0.

a) what is the kinetic energy of the block as it passes through x = 2.0 m?

b) what is the maximum kinetic energy of the block between x = 0 and x = 2.0 m

Wouldn't I get the same answer for both a and b?

I did the following:

** S = integral sign

W = S F(x)dx = Kf - Ki

with xi = 0 and xf = 2.0:

S F(x)dx = 2.5x -x^3/3 --> 2 1/3 J

Wouldn't the ans for both a and be be 2 1/3 J?

Thanks!