### Physics Past Questions

6

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
JAMB 1999
7
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
JAMB 1999
8
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
JAMB 1999
9
A solid weigh 10 .00 N in air, 6 N when fully immersed in water and 7 . 0 N when fully immersed in a liquid X. Calculate the relative density of the liquid, X.
• A. 5/3
• B. 4/3
• C. 3/4
• D. 7/10
JAMB 1999
10
When temperature of a liquid increases, its surface tension
• A. Decreases
• B. Increases
• C. Remain Constant
• D. Increases then decreases
JAMB 1999