If the stress on a wire is 107NM-2 and the wire is stretched from its original length of 10.00 cm to 10.05 cm. The young’s modulus of the wire is
- A. 5 . 0 x 104 Nm-2
- B. 5 . 0 x 105 Nm-2
- C. 2 . 0 x 108 Nm-2
- D. 2 . 0 x 109 Nm-2
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
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
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
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
Particles of mass 10\(^{-2}\)kg 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
Two bodies have masses in the ratio 3:1. They experience forces which impart to them acceleration in the ratio 2:9 respectively. Find the ratio of forces the masses experienced.
- A. 1 : 4
- B. 2 : 1
- C. 2 : 3
- D. 2 : 5
The inner diameter of a test tube can be measured accurately using a?
- A. micrometer screw guage
- B. pair of dividers
- C. metre rule
- D. pair of vernier calipers