Question

A 5kg object starts off at ? = 0 travelling at ?x= +10m/s .  During its motion, it is subject to a position-dependent force given by:

?net(?) = +480 + 2 ≤ ? ≤ 4,

−120?  + 4 ≤ ? ≤ 6,

0 ??ℎ??????

When the object arrives at ? = +4? (parts a-b):

a. Calculate the work done on the object.

b. Calculate the speed of the object.

When the object arrives at ? = +8? (parts c-e):

c. Calculate the total net work done on the object up until this point.

d. Calculate the speed of the object

e. Suppose the net force between +4 ≤ ? ≤ 6 is entirely due to a non-conservative force (and all other forces are

conservative), how much total mechanical energy is lost to the environment during the whole trip?

Answer 1

Here we apply definition of work and work energy theorem.