2001 - JAMB Physics Past Questions and Answers - page 1

(p - 760)/(0 - 760) = (h - 0)/(80 - 0)

∴ (p - 760)/-760 = (20 - 0)/80

80(p-760) = -760(20-0)

∴80p - 60800 = -15200

80p = 60800 - 15200

80p = 45600

∴ p = 45600/80

p = 570mmHg

At the height of 10m, its total energy is potential, given by P.E. = mgh = 1 x 10 x 10 = 100J.

But as the stone descends, its potential energy decreases, while its kinetic energy increases.

Half way during the fall, (h = 5m), its P.E. = 50J, and consequently, its K.E. should be 50J, such that from the principle of conservation of energy, the total energy of the stone at any instant should be conserved.

If the bob is fully immersed in the water, then the volume of water displaced will be equal to the volume of the bob = 4/3πr³, where r is the radius of the bob.

This volume of water in the cylinder = πr²l, where r = radius of the cylinder, and l = level of water rose in the cylinder.

Therefore, π x r² x l = 4/3 x π x 3³

Then r² = 36

r = √36

r = 6cm

The resultant of two forces acting on an object is maximum when the angle between them is zero, during which the tow forces are parallel and pointing in the same direction

When ever a ray of light is incident on a plane mirror at an angle of incidence l, if the mirror is then rotated through an angle θ, then the reflected ray is rotated through an angle twice θ

So if θ = 35°, then the reflected ray is rotated through 2 x 10^o = 20°

The extra lens in the terrestrial telescope mounted at the middle between the objective lens and the eye piece is to re-invert the image so that it is upright.