2003 - JAMB Physics Past Questions and Answers - page 1

K = 500Nm^-1; M = 5 x 10^-3kg; e = 0.02m;

g = 10ms^-2. The elastic potential energy stored in the compressed spring is given by = ¹/₂Ke², and the energy is transformed into gravitational potential energy = mgh, thus from the principle of energy conversion, we have that mgh = ¹/₂Ke²

5 x 10^-3 x 10 x h = ¹/₂ x 500 x (0.02)²

∴ h = 1 x 500 x 0.02 x 0.022 x 5 x 10^-3 x 10

= 5 x 2 x 0.02___10^-1

= 10 x 0.02 x 10 = 2

∴ h = 2m

Pressure = ^F/_A = pgh, where p = density, h = depth and g = 10ms^-2

But F = P x A

∴ Force exerted by the load test tube = cross-sectional Area x Pressure

i.e F = A x pgh

= 0.028m or 2.8m

Vol = cross-sectional area x length

∴ vol. of water disharged per sec

= 60ms^-1 x 0.5m

= 30m³ 5^-1

=> Vol. of water discharged in the said 20s

= 30m³ x 20 = 600m³

∴ vol. of the container = 600m³

When an object is on the verge of sliding on an inclined plane, the force of static friction is at its maximum value. The coefficient of static friction (µ) is related to the angle of inclination (θ) at which sliding begins by the following equation:

µ = tan(θ)

In this case, θ = 30°. Therefore:

µ = tan(30°) = 1/√3

Surface tension - The tendency of a liquid surface to behave as an elastic skin

Pressure P = ^F/_A

= ^F/_πr²

AS the stone is whirled round and te string suddenly cuts, say at A, B, C or D. The stone will fly off in the direction indicated V_A, V_B, V_C or V_D respectively which is tangential to the circular path

Since the lever is a uniform one, its center of gravity will be acting half way (i.e 45cm)

∴from the principle of moments,

F x 45 = 30 x 30

∴ F = (30 x 30) / 45 = 20N

A satellite is said to be in a parking orbit if its period is exactly equal to the period of the earth as it turns its own orbit;. which is about 24hrs