Q: A block of mass 2.0 kg slides on a rough horizontal plane surface. Let the speed of the block at a particular instant is 10 m/s. It comes to rest after travelling a distance of 20 m. Which one of the following could be the magnitude of the frictional force?
(a)10 N
(b)20 N
(c)40 N
(d)50 N
Correct Answer: (c)