Explore BrainMass

Force Problem

The only force acting on a 2.4 kg body as it moves along the x axis varies as shown in Fig. 7-33 (attached). The velocity of the body at x = 0 is 4.0 m/s.

(a) What is the kinetic energy of the body at x = 3.0 m?
(b) At what value of x will the body have a kinetic energy of 8.0 J?
(c) What is the maximum kinetic energy attained by the body between x = 0 and x = 5.0 m?


Solution Preview

We know that work done is given by the change in kinetic energy.
That is,
W = Final KE - Initial KE = (1/2)m vf^2 - (1/2)m vi^2 ....(1)
where vf and vi are the initial and final velocities.

also, we know that the area under the force vs distance curve gives the work done.

We have, m = 2.4 Kg
v at x = 0, = 4 m/s

a) The initial KE = (1/2)m v^2 = 0.5 * 2.4 * 4^2 = ...

Solution Summary

The solution uses the area under the graph provided to answer the question of forces and work done.