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 $60\mathrm{\%}$ 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. ${240}^{\circ }$