Question

A 100. N block sits on a rough horizontal floor. The coefficient of sliding friction between the block and the floor is 0.250. A horizontal force of 90.0 N acts on the block for 3.00 seconds. Calculate the velocity of the block after 3.00 seconds if it starts from rest.

Answer 1

     Using the Impulse Theorem, we have:

$F_{r}.\Delta t=m.\Delta v \\ (F-F_{at}).(3-0)= \frac{P}{g} .(v-0) \\ (90-100.0,25).3= \frac{100v}{10} \\ v= \frac{3.65}{10} \\ \boxed {v=19,5 m/s}$

If you notice any mistake in English, please let me know, because I'm not native.