1.
When sugar at the bottom of a glass of water gradually dissolves, the water level does not change apprecialby. Whcih of the following statements explains this?
Correct Answer
C. The volume of the sugar molecules does not change when the sugar dissolves
Explanation
Concept of Matter
2.
Water does not drip trhough an open umbrella of silk material unless the inside of the umbrella is touched. Which of the following phenomenon is repsonsible for this?
Correct Answer
A. Surface tension
Explanation
Concept of Matter
3.
The odour of a leaking gas is percieved by the molecular theory of matter?
Correct Answer
D. Expansion
Explanation
Concept of Matter
4.
A boy travels 8 km eastward to a point B and then 6km norhtward to another point C. Determine the difference between the magnitude of displacement of the boy and distance travelled by him.
Correct Answer
C. 10.0km
Explanation
Position, Distance, Displacement and Speed
5.
A particle starts at rest and moves with a constant acceleration of 0.5ms-2 calculate the time taken by the particle to cover a distance of 25m.
Correct Answer
C. 10.5s
Explanation
Position, Distance, Displacement and Speed
6.
A bus travelling at 15ms-1 accelerates uniformly at 4ms-2. What is the distance covered in 10s.
Correct Answer
C. 350m
Explanation
Position, Distance, Displacement and Speed
7.
A body moves with a constant speed but has no acceleration. This possibly ____
Correct Answer
A. Moves in a straight line
Explanation
When a body moves with a constant speed but has no acceleration, it means that its velocity is not changing. Since acceleration is the rate of change of velocity, a body with no acceleration implies that its velocity remains constant over time. In such a scenario, the body will continue to move in a straight line, as there are no forces acting on it to cause it to change direction. Therefore, the correct answer is that the body moves in a straight line.
8.
What type of motion dies the skin of a talking drum perform when it is being struck with the drum stick?
Correct Answer
C. Brownian motion
9.
A loaded test-tube which floats upright in water is carefully and slightly depressed and released. Which of the following best describes the subsequent motion of the test tube?
Correct Answer
C. Translational
Explanation
When the loaded test-tube is slightly depressed and released, it will undergo translational motion. Translational motion refers to the movement of an object from one place to another without any rotation or spinning. In this case, the test-tube will move in a straight line up and down, without any circular or rotational motion.
10.
Which type of motion does a body undergo when acted upon by a couple?
Correct Answer
C. Rotational
Explanation
When a body is acted upon by a couple, it undergoes rotational motion. A couple is a system of forces that consists of two equal and opposite forces acting on a body, but not along the same line. This creates a turning effect or torque on the body, causing it to rotate around an axis. Therefore, the correct answer is rotational.
11.
The driver of a car moving with a uniform speed of 4ms-1 observes a truck approaching in the opposite direction with a speed of 20ms-4. Calculate the speed of the car relative to that old truck.
Correct Answer
B. 2.0ms-1
Explanation
The speed of the car relative to the old truck can be calculated by subtracting the speed of the truck from the speed of the car. In this case, the car is moving with a speed of 4ms-1 and the truck is approaching with a speed of 20ms-1. Therefore, the relative speed of the car with respect to the old truck is 4ms-1 - 20ms-1 = -16ms-1. However, since speed is a scalar quantity and cannot be negative, the magnitude of the relative speed is taken, resulting in 16ms-1. Therefore, the correct answer is 2.0ms-1.
12.
A ball of mass 0.5kg moving at 10ms-1 collides with another ball of equal mass at rest. If the two balls moving off together the impact. Calculate their common velocity.
Correct Answer
C. 5.0ms-1
Explanation
When two objects collide, the law of conservation of momentum states that the total momentum before the collision is equal to the total momentum after the collision. In this case, the first ball has an initial momentum of (0.5 kg)(10 m/s) = 5 kg·m/s, while the second ball is at rest with an initial momentum of 0 kg·m/s. After the collision, the two balls move off together, so their final momentum is equal. Therefore, the final momentum is also 5 kg·m/s. Since the two balls have equal mass, their final common velocity can be calculated using the equation final momentum = (total mass)(final velocity). Solving for the final velocity gives us (5 kg·m/s) / (1 kg + 1 kg) = 2.5 m/s. Therefore, the common velocity of the two balls after the collision is 2.5 m/s, or 2.5 ms-1 when rounded to one decimal place.
13.
A ball of mass 5.0kg hits a smooth vertical wall normally with a speed of 2ms-1 and rebounds with the same speed. Determine the inpulse experienced by the ball.
Correct Answer
A. 20.0kgms-1
Explanation
When the ball hits the wall and rebounds with the same speed, it experiences a change in momentum. The impulse experienced by an object is equal to the change in momentum it undergoes. In this case, since the ball rebounds with the same speed, its initial momentum is equal in magnitude but opposite in direction to its final momentum. Therefore, the change in momentum is equal to the initial momentum. The initial momentum is given by the product of the mass and the initial velocity, which is (5.0 kg)(2 m/s) = 10.0 kgm/s. Hence, the impulse experienced by the ball is 10.0 kgm/s.
14.
What would be the most appropraite equation to represent the distance x travelled by a body moving on a straight road with a constant speed?. (Note other symbols have their usual meanings)
Correct Answer
x=ut
Explanation
The equation x=ut represents the distance x travelled by a body moving on a straight road with a constant speed. In this equation, x represents the distance, u represents the constant speed, and t represents the time taken to travel that distance. This equation is derived from the formula distance = speed × time, where the speed remains constant throughout the motion. Therefore, x=ut is the most appropriate equation to represent the distance travelled by a body with a constant speed.
15.
Which of the following instruments is suitable for making the most accurate measurement of the internal diameter of a test tube?
Correct Answer
B. A pair of callipers
Explanation
A pair of callipers is the most suitable instrument for making accurate measurements of the internal diameter of a test tube. Callipers have two arms, one of which can be adjusted to fit inside the test tube, allowing for precise measurements. A meter rule and a tape rule are not suitable for measuring small dimensions accurately. A micro-meter-screw-gauge is used for measuring very small dimensions with high precision, but it may not be necessary for measuring the internal diameter of a test tube.