Post Utme Physics Past Questions and Answers

Question 91:

A bead traveling on a straight wire is brought to rest at \(0.2 \mathrm{~m}\) by friction. If the mass of the bead is \(0.01 \mathrm{~kg}\) and the coefficient of friction between the bead and the wire is \(0.1\), determine the work done by friction.

A. \(2 \times 10^{-4} \mathrm{~J}\)
B. \(2 \times 10^{3} \mathrm{~J}\)
C. \(2 \times 10^{1} \mathrm{~J}\)
D. \(2 \times 10^{2} \mathrm{~J}\)

Question 92:

A machine whose efficiency is \(60 \%\) has a velocity ratio of 5 .
If a force of \(500 \mathrm{~N}\) is applied to lift a load of \(P(N)\), what is the magnitude of \(P\) ?

A. \(750 \mathrm{~N}\)
B. \(4166 \mathrm{~N}\)
C. \(500 \mathrm{~N}\)
D. \(1500 \mathrm{~N}\)

Question 93:

A mass of gas at \(7^{\circ} \mathrm{C}\) and \(70 \mathrm{~cm}\) of mercury has a volume of 1200 cm3.
Determine its volume at \(27^{\circ} \mathrm{C}\) and a pressure at \(75 \mathrm{~cm}\) of mercury.

A. \(1200 \mathrm{~cm}^{3}\)
B. \(1378 \mathrm{~cm}^{3}\)
C. \(4320 \mathrm{~cm}^{3}\)
D. \(4629 \mathrm{~cm}^{3}\)

Question 94:

A motor tyre is inflated to a pressure of \(2.0 \times 10^{5} \mathrm{Nm}^{-2}\) when the temperature of air is \(27^{\circ} \mathrm{C}\).

What will be the pressure at \(87^{\circ} \mathrm{C}\) assuming the volume does not change?

A. \(2.6 \times 10^{-5} \mathrm{Nm}^{-2}\)
B. \(2.4 \times 10^{-5} \mathrm{Nm}^{-2}\)
C. \(2.2 \times 10^{-5} \mathrm{Nm}^{-2}\)
D. \(1.3 \times 10^{-5} \mathrm{Nm}^{-2}\)

Question 95:

A beam of light is incident from air to water at an angle of \(30^{\circ}\). Find the angle of refraction if the refractive index of water is \(4 / 3\).

A. \(15^{\circ}\)
B. \(18^{\circ}\)
C. \(22^{\circ}\)
D. \(240^{\circ}\)