A block of mass 1 kg is pushed up a surface inclined to horizontal at an angle of 30° by a force of 10 N parallel to the inclined surface (Fig. 6.15). The coefficient of friction between block and the incline is 0.1. If the block is pushed up by 10 m along the incline, calculate
(a) work done against gravity
(b) work done against force of friction
(c) increase in potential energy
(d) increase in kinetic energy
(e) work done by applied force.
Mass of the block m = 1kg
Angle of inclination = 
Coefficient of friction = 0.1
Displacement = 10 m
a) Work done against gravity
= 
b) Work done against friction
= 
c) Vertical raise in height h 
∴ change in P.E.
d) Applying work energy theorem,
-(1)
Putting these in equation (1),
We get,
∴ there is a decrease in the kinetic energy by 41.3 J
e) Applied force F = 
Displacement d = 
Work done W by the force F is given as
= 
=
