Question Library

Given the velocity of sound at \( 15^\circ C \): \(v_0 = 340 \, \text{m/s}\) The absolute temperatures are: \(T_0 = 15 + 273.15 = 288.15 \, \text{K}\) \(T = 47 + 273.15 = 320.15 \, \text{K}\) We use the formula for the velocity of sound: \(v = v_0 \sqrt{\frac{T}{T_0}}\) Substituting the known values: \(v = 340 \times \sqrt{\frac{320.15}{288.15}}\) Calculating the ratio of temperatures: \(\frac{320.15}{288.15} \approx 1.111\) Taking the square root: \(\sqrt{1.111} \approx 1.054\) Finally, calculating the new velocity: \(v \approx 340 \, \text{m/s} \times 1.054 \approx 358.6 \, \text{m/s}\) The velocity of sound in air at \( 47^\circ C \) is approximately: \(v \approx 358.6 \, \text{m/s}\)

No expanded working has been attached for this question yet. The verified answer is Option A.

The normal reaction/force on a body on a horizontal surface is R = mg; but that on a body on an inclined surface is R = mgCos\theta.

The force causing the ball to roll down the inclined plane is greater than the one pulling it up, resolving the force in its component we have \(mgsin\theta\) therefore the Net Force acting on the ball = \(mgsin\theta\) - F

Motion of charged particles in Magnetic field qvb = \(\frac{Mv^2}{r}\) where q = e Introducing Period (T) as time taken to complete one orbit = \(\frac{2\piM}{qe}\)

No expanded working has been attached for this question yet. The verified answer is Option B.

specific latent heat of vapourization is the amount of heat energy needed to change 1kg of liquid to vapour without a temperature change. The heat absorbed by the liquid at the beginning of vapourization is \(8 \times 10^3\)J and heat absorbed after the change of stage is \(53 \times 10^3\)J. therefore, the total heat energy needed to change the liquid completely to vapour is Q = \(53 \times 10^3 - 8 \times 10^3 J = 45 \times10^3\)J Recall, Q = mL Where, L = specific latent heat of vapourization Q = mL L = \(\frac{ Q}{m}\) = \(\frac{ 45 \times 10^3}{0.02}\) L = \(2.25 \times10^6JKg^{-1}\)

No expanded working has been attached for this question yet. The verified answer is Option A.

A total solar eclipse happens when the Moon passes between the Earth and the Sun, blocking the Sun’s light. Because the Earth’s diameter is much larger than the Moon’s, the Moon’s shadow covers only a small area on Earth, so only people in the narrow “path of totality” see the Sun fully covered.

Velocity = frequency x wavelength v = 18cm/s, wavelength = 3.6cm, then F = 5hertz therefore, the speed of the wave in the shallow water = 5 x 2 = 10cm/s NOTE; as a general rule, the frequency of a wave remains constant while speed and wavelength change as it travels from one medium to another.

No expanded working has been attached for this question yet. The verified answer is Option A.

No expanded working has been attached for this question yet. The verified answer is Option C.

Using de Broglie wavelength formula: \(\lambda\) = \(\frac{h}{p}\) P = momentum = mass x velocity = 9.1x 10\(^{-31}\) x 2.0 x 10\(^6\) = 1.82 \times 10\(^{ −24}\) kg m/s \(\lambda\) = \(\frac{6.6. \times 10^{-34}}{1.82 \times 10^{ −24}}\) = 3.63 x 10\(^{-10}\) m

During change of state, there is no change in temperature, for a solid to change to liquid, heat must be supplied and it starts rising again after melting has taken place. therefore, the temperature rises before melting takes place remains steady during melting, and keeps rising after melting.

No expanded working has been attached for this question yet. The verified answer is Option A.