Physics Past Questions and Answers

Particles of mass 10^-2kg is fixed to the tip of a fan blade which rotates with angular velocity of 100rad-1. If the radius of the blade is 0.2m, the centripetal force is

A 2 N
B 20 N
C 200 N
D 400 N

Question 1627:

A lead bullet of mass 0.05kg is fired with a velocity of 200ms\(^{-1}\) into a lead block of mass 0.95kg. Given that the lead block can move freely, the final kinetic energy after impact is

A 50 J
B 100 J
C 150 J
D 200 J

Question 1628:

A ball of mass 0.1kg is thrown vertically upwards with a speed of 10ms-1 from the top of a tower 10m high. Neglecting air resistance, its total energy just before hitting the ground is
(take g = 10ms-2)

A 5 J
B 10 J
C 15 J
D 20 J

Question 1629:

A car of mass 800kg attains a speed of 25m/s in 20 secs. The power developed in the engine is

A 1 . 25 x 104 W
B 2 . 50 x 104 W
C 1 . 25 x 106W
D 2 . 50 x 106 W

Question 1630:

When the brakes in a car are applied, the frictional force force on the tyres is

A Is a disadvantage because it is in the direction of the motion of the car
B Is a disadvantage because it is in the opposite direction of the motion of the car
C Is an advantage because it is in the direction of the motion of the car
D Is an advantage because it is in the opposite direction of the motion of the car