CSEC Physics Paper 2 May/June 2015 - Free CXC Past Paper with Answers

This question concerns thermal heat capacities.

In the box below, state the equation that relates $C$ to $c$.

State the name of the physical quantity that each letter represents. $C$: $c$:

Distinguish between '$C$' and '$c$'.

A substance which has a melting point of $80 \text{ °C}$ is cooled from $90 \text{ °C}$ to a complete solid at its melting point.

Sketch a graph in Figure 1 to represent the statement above.

Figure 1

Temperature (°C) Time (s)

A physicist converted $2 \text{ kg}$ of water at $37 \text{ °C}$ to steam at $100 \text{ °C}$. Assuming no heat is lost, calculate the amount of energy needed.

Specific heat capacity of water $= 4200 \text{ J kg}^{-1} \text{ K}^{-1}$ Specific latent heat of vaporization of water

to heat the water to $100 \text{ °C}$

to heat the water from $100 \text{ °C}$ to steam at $100 \text{ °C}$.

to completely convert the water from $37 \text{ °C}$ to steam at $100 \text{ °C}$.

(Specific heat capacity of water $= 4200 \text{ J kg}^{-1} \text{ K}^{-1}$) (Specific latent heat of vaporization of water )

Explain what is meant by the term 'electrical resistance'.

Complete Table 2 to provide information regarding electrical meters.

TABLE 2

Calculate the reading on EACH of the meters shown in the circuit in Figure 2 when the switch is closed.

Figure 2

Reading on $A_1$

Reading on $A_2$

State Newton's three laws of motion.

In a crash test, a car travelling at a constant velocity of $26 \text{ m s}^{-1}$ crashes into a wall and is brought to rest.

Calculate the initial momentum of a $70 \text{ kg}$ test dummy in the car before the crash.

Calculate the average force exerted on the dummy by the seatbelt during the crash if the duration of the collision is $0.1$ seconds.

With the removal of all protective features, the dummy was subjected to another crash test with the same initial speed. This time it was subjected to a 'lethal' decelerating force of $45 \text{ 000 N}$. Calculate the duration of this collision.

With the removal of all protective features, the dummy was subjected to another crash test with the same initial speed. This time it was subjected to a 'lethal' decelerating force of $45\ 000\ \text{N}$. Calculate the duration of this collision.

Describe how the graph of Volume versus Temperature (in Celsius) of a gas can be used to derive the Kelvin scale?

State the mathematical relationship between the Kelvin and Celsius temperature scales.

A piston traps a mass of gas in a cylinder. At $25 \text{ °C}$, the pressure of the gas is $5$ atmospheres when its volume is $50 \text{ ml}$.

Calculate the volume of the gas if its pressure drops to $1$ atmosphere at constant temperature.

After resetting the piston, the gas returns to its initial pressure and volume. If the volume is now fixed while the gas is heated to $60\ \text{°C}$, calculate the final pressure of the gas.

Copy Figure 3 and draw the ray shown as it emerges on the other side of the lens and its relation to the focus. Show the principal axis and the focal length.

Space for diagram.

Write, in words or symbols, the formula for the magnification of an object.

An object $AB$ is placed $20\ \text{cm}$ in front of a converging lens of focal length $F$, $10\ \text{cm}$ as seen in Figure 4.

Calculate the position of the image formed and state on what side of the lens it is located.

Calculate the magnification of the image formed.

Is the image formed real or virtual?