A 30.0-kg crate is initially moving with a velocity that has magnitude 3.90 m/s in a direction 37.0o west of north. How much work must be done on the crate to change its velocity to 5.62 m/s in a direction 63.0o south of east?
Solution 30E Step 1 of 3: In the given problem we need to calculate work done in changing the velocity of m=30kg carte from v = 3.9 m/s to v = 5.62 m/s. We are not considering the directions, as work i f done does not depend on path followed, it depends only on the initial and final positions. From work energy theorem , the work done on the carte will be equal to the change in kinetic energy of the carte. That is, W = KE = KE KE f i Where W is work done, initial kinetic energy KE and final kinetic energy KE . i i Step 2 of 3: Using KE= mv 2 2 W= mv1 2- mv 2 2 f 2 i 1 2 2 W= m(2 f -v i ) Where v is final velocity and v is initial velocity. f i