Question 1 Friction force can be reduced to a great extent by
(a) lubricating the two moving parts
(b) using ball bearing between two moving parts
(c) introducing a thin cushion of air maintained between two relatively moving surfaces (d) all the above
Question 2 Force exerted on a body can change its
(a) kinetic energy
(b) direction of motion
(c) speed
(d) momentum
Question 3 A block is released from the top of a smooth inclined plane. Another block of the same mass is allowed to fall freely from the top of the inclined plane. Both blocks reach the bottom of the plane
(a) with equal speed
(b) in equal interval of time
(c) with equal kinetic energy
(d) with equal momentum
Question 4 Which of the following expression does not represent the force acting on the body of mass m
(a) GMem/(Re)2
(b) ma
(c) μN
(d) 6ηπrv
Question 5 A body of mass m is resting on the floor. A minimum amount of force is applied on the body and the force continues to act on the body as it moves. If the coefficient of static and dynamic friction are 0.4 and 0.3 respectively, then the acceleration of the body is
(a) 0
(b) 3.98
(c) 0.98
(d) 4.98
Answer (1) d. (2) a, b, c, d (3) a and c (4) d (5) c
