# Question 1

1.1 A constant net force acts on an object moving in a straight line. Which ONE of
the following quantities associated with the object will remain constant during
the motion?
A. Velocity
B. Momentum
C. Acceleration
D. Kinetic energy (2)

1.2 The weight of an object on the surface of the Earth is w. What will be the
weight of the object on the surface of another planet of the SAME mass as
that of the Earth, but TWICE the radius of the Earth?

1.3 The diagram below shows a cricket player moving his hands downwards from
position 1 to 2 to 3 while catching a ball.

Which ONE of the following statements CORRECTLY explains why the
cricket player moves his hands downwards?

A. The impulse on the ball is decreased.
B. The change in momentum of the ball is increased.
C. The change in momentum of the ball is decreased.
D. The time it takes to change the momentum of the ball is increased. (2)

1.4 Consider the motion of a small stone thrown vertically upwards until it reaches
its maximum height.
Ignore the effects of friction.
Which ONE of the following combinations of graphs CORRECTLY shows how
the momentum p and the gravitational potential energy U of the stone change
with time?

1.5 A boy and a girl, having DIFFERENT masses, are initially at rest at point P.
They slide down different paths of a water slide, as shown in the diagram
below.
Ignore the effects of friction.

Consider the statements below regarding the boy and the girl:
I. Only conservative forces act on both the boy and the girl while they are
sliding downwards.
II. The boy and the girl each have the same gravitational potential energy
at point P.
III. On reaching point Q, the speed of the girl is equal to that of the boy.

Which of the above statements is/are CORRECT?
A. I only
B. I and III only
C. II and III only
D. I, II and III (2)

1.6 An astronomer observes that the light spectrum of a star has been blue
shifted.
How have the observed frequency of light from the star and the distance
between the star and Earth changed?

1.7 A small negative point charge (q) is situated halfway between two identical
spheres, P and Q, carrying IDENTICAL charges, as shown below.

Sphere P exerts an electrostatic force of magnitude F on sphere Q. What is
the magnitude of the net electrostatic force experienced by the point charge?

1.8 Consider the statements below regarding AC power and DC power:
I. AC voltage can be changed during AC power transmission.
II. DC power transmission requires transformers.
III. AC power transmission is more energy efficient.

Which of the above statement(s) is/are CORRECT?
A. I only
B. II only
C. I and III only
D. II and III only (2)

1.9 In the circuit diagram below, all resistors are IDENTICAL. Ignore the internal
resistance of the cell and the resistance of the connecting wires.

When switch S is CLOSED, the reading on voltmeter V1 is 3 V.
What will be the reading on voltmeter V2?
A.1 V
B. 1,5 V
C. 2 V
D. 3 V (2)

1.10 Some of the energy levels of an atom are represented in the diagram below.

E0 represents the ground state energy.
Which ONE of the energy transitions below represents the absorption of light
of the lowest frequency by the atom?
A. E0 to E4
B. E1 to E3
C. E3 to E4
D. E0 to E3 (2)
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