A block of mass 5 kg rests on a rough horizontal floor
PHYSICS · Subjective · CBSE · Physics · Work, Energy and Power · Work, Energy and Power
Problem
A block of mass 5 kg rests on a rough horizontal floor. It is pulled through a distance of 10 m by a force of 20 N acting at an angle of 30° above the horizontal. The coefficient of kinetic friction between the block and the floor is 0.20. Take g=10ms−2.
(a) Calculate the work done separately by
(i) the applied force,
(ii) the frictional force,
(iii) the weight of the block, and
(iv) the normal reaction of the floor during the displacement.
(b) Obtain the net work done on the block and hence find the change in its kinetic energy.
(c) If the block started from rest, determine its speed after moving the given distance.