1.
Define 1. moment.
2. Momentum.
3. Specific heat capacity.
4. electromotive force.
5. Half live time.
2.
Fig. 1.1 shows the speed-time graph for the motion of a car.
The mass of the car is 1200 kg.
(a) Calculate, for the first 20 s of the motion,
(i) the distance travelled by the car,
distance = ...........................................................[2]
(ii) the acceleration of the car,
acceleration = ...........................................................[2]
(iii) the resultant force acting on the car.
resultant force = ...........................................................[2]
(b) Describe the motion of the car in the period of time from 25 s to 40 s.
...................................................................................................................................................
...............................................................................................................................................[1]
[Total: 7]
3.
All the sides of a plastic cube are 8.0 cm long. Fig. 3.1 shows the cube.
The mass of the cube is 0.44 kg.
(a) Explain what is meant by mass.
...............................................................................................................................................[1]
(b) (i) Calculate the density of the plastic from which the cube is made.
density = ...........................................................[2]
(ii) The density of one type of oil is 850 kg / m3.
State and explain whether the cube floats or sinks when placed in a container of this oil.
...........................................................................................................................................
.......................................................................................................................................[1]
(c) On the Moon, the weight of the cube is 0.70 N.
(i) Calculate the gravitational field strength on the Moon.
gravitational field strength = ...........................................................[2]
Total= 6
4.
A mass of 0.20 kg of a substance is initially solid.
It is heated at a steady rate of 500 W.
The graph shows how the temperature of the substance changes with time.
What is the specific latent heat of fusion of the substance?
Correct Answer
C. C. 500000J/kg
Explanation
The specific latent heat of fusion is a measure of the amount of energy required to change a substance from a solid to a liquid at a constant temperature. In this question, the substance is initially solid and is being heated at a steady rate. The graph shows that as time increases, the temperature of the substance remains constant for a period of time before increasing again. This indicates that during this period of constant temperature, the substance is undergoing a phase change from solid to liquid, and the energy being supplied is being used to overcome the latent heat of fusion. Therefore, the specific latent heat of fusion of the substance is 500000J/kg, as indicated by option C.
5.
Which quantity is measured in (NS)
Correct Answer
A. A. Impulse.
Explanation
Impulse is a quantity that is measured in (NS), which stands for Newton-seconds. Impulse is defined as the change in momentum of an object, and it is calculated by multiplying the force applied to an object by the time interval over which the force is applied. Since force is measured in Newtons and time is measured in seconds, the product of these two units gives us the unit of impulse, which is Newton-seconds (NS). Therefore, the correct answer is A. Impulse.
6.
Which measurement can be made using a micrometer screw gauge?
Correct Answer
B. B.the diameter of a wire.Â
Explanation
A micrometer screw gauge can be used to measure the diameter of a wire. This instrument is designed with a screw mechanism that allows for precise measurements of small distances, such as the diameter of a wire. By adjusting the screw, the user can bring the two measuring faces of the micrometer into contact with the wire, and the reading on the scale provides the diameter measurement.
7.
The diagram shows an experiment to find the density of a liquid.
What is the density of the liquid?
Correct Answer
B. B.2.0 g / cm^{3}
Explanation
In the diagram, the liquid is poured into a graduated cylinder and its volume is measured. The mass of the liquid is also measured using a balance. Density is calculated by dividing the mass of the liquid by its volume. Looking at the diagram, the mass of the liquid is greater than its volume, indicating that the liquid is denser. Among the given options, only option B, 2.0 g / cm3, represents a higher density value. Therefore, the correct answer is B.2.0 g / cm3.
8.
A beam pivoted at one end has a force of 5.0 N acting vertically upwards on it as shown. The
beam is in equilibrium.
What is the weight of the beam?
Correct Answer
A. A. 2.0 N
Explanation
The beam is in equilibrium, which means that the sum of the forces acting on it must be zero. Since there is a force of 5.0 N acting vertically upwards on the beam, there must be an equal and opposite force acting downwards to balance it. This downward force is the weight of the beam. Therefore, the weight of the beam is 5.0 N.
9.
A car has a mass of 1000 kg and a momentum of 12000 kg m/ s.
What is its kinetic energy?
Correct Answer
C. C. 72 KJ
Explanation
The kinetic energy of an object can be calculated using the formula KE = 1/2 * mass * velocity^2. In this case, the momentum is given, which is equal to mass * velocity. Rearranging the equation, we can solve for velocity: velocity = momentum / mass. Plugging in the given values, we get velocity = 12000 kg m/s / 1000 kg = 12 m/s. Now we can calculate the kinetic energy using the formula: KE = 1/2 * 1000 kg * (12 m/s)^2 = 1/2 * 1000 kg * 144 m^2/s^2 = 72,000 J = 72 KJ. Therefore, the correct answer is C. 72 KJ.
10.
The diagram shows a simple mercury barometer alongside a mercury manometer. The
manometer contains some trapped gas. What is the pressure of the trapped gas?
Correct Answer
D. D. 86 cm of mercury.
Explanation
The pressure of the trapped gas can be determined by comparing the heights of the mercury columns in the barometer and manometer. In the barometer, the height of the mercury column represents the atmospheric pressure, which is typically around 76 cm of mercury. In the manometer, the height of the mercury column represents the sum of the atmospheric pressure and the pressure of the trapped gas. Since the height of the mercury column in the manometer is 86 cm, the pressure of the trapped gas is 86 cm of mercury.
11.
The diagram shows a satellite that is moving at a uniform rate in a circular orbit around the Earth.
Which statement describes the motion of this satellite?
Correct Answer
B. B.It is accelerating because its velocity is changing.
Explanation
The correct answer is B. It is accelerating because its velocity is changing. In circular motion, the direction of the velocity is constantly changing, even if the speed remains constant. Acceleration is defined as a change in velocity, which includes changes in direction. Since the satellite in the diagram is constantly changing its direction as it moves in a circular path, it is experiencing acceleration.
12.
Which statement about an object moving in a straight line through air is correct?
Correct Answer
C. C. When it moves at a steady speed, the resultant force acting on it is zero.
Explanation
When an object moves at a steady speed in a straight line through air, it means that the forces acting on it are balanced. In this case, the force of air resistance is equal and opposite to the force applied to the object, resulting in a net force of zero. This is in accordance with Newton's first law of motion, which states that an object will continue to move at a constant velocity (steady speed) unless acted upon by an external force. Therefore, option C is correct.
13.
The diagram shows some ice being used to lower the temperature of some warm water.
What is the main process by which the water at the bottom of the glass becomes cool?
Correct Answer
C. C. convection
Explanation
The main process by which the water at the bottom of the glass becomes cool is convection. Convection is the transfer of heat through the movement of a fluid, in this case, the warm water. As the ice cools the water at the top of the glass, it becomes denser and sinks to the bottom, displacing the warmer water. This creates a continuous circulation of the water, allowing the cooler water at the top to move down and be replaced by warmer water. This process helps to evenly distribute the cooling effect of the ice throughout the glass.