​During a snooker competition, a 200 grams ball A moving with velocity V! as show in the diagram above, collides head-on with an identical ball B that was at rest. After the collision, ball A remains at rest while ball B moves on with a velocity of 4m/s.
a). With what speed was ball A moving before the collision?                                             (1 marks)
b). What is the momentum of the ball B after the collision?                                              (2 marks)
c). What is the momentum of ball A after the collision?                                                    (1mark)
d). What are the directions of the forces exerted by balls on each other?                           (2marks)
e). Which of the three laws of motion (Newton’s Laws) is being applied in part a). above?   (1 mark) 

QUESTION 33
A boy can carry a 2kg box and walk one meter to the right. Then he raises it by 1m and places it on a shelf.
a). Explain why the boy cannot do any work in carrying the box horizontally.                     (2 marks)
b). Calculate the work the boy does in raising the box vertically and placing it on the shelf. (2 marks)
c). If the boy takes one minute to raise the box vertically, what is the power used in raising the box?
                                                                                                                                 (2 marks)
d). What form of energy does the box have as a result of being raised and placed on the shelf? (1mark) 

QUESTION 37
a) How many changes in phase are involved in working out the total amount of heat required to raise the temperature of ice at -15°C to steam at 115°C? (1 mark)

b) In a hot climate, the inhabitants often wear while coloured clothes. Explain why they do that? (1 mark)

c) An electric boiler with power rating of 125 kW is used to complete evaporate water at a temperature of 100°C in 2 minutes. If the initial temperature of water is 20°C, how much in kilograms is the mass of the water? (3 marks)

d) Explain the difference between heat and temperature. (1 mark)

e) You bought two cooking pots with same masses and volumes. One is made of copper which has a specific heat capacity of 400J/kg°C and the other is made of aluminum whose specific heat capacity is 900J/kg°C . If the same amount of heat is applied to both cooking pots with equal amount of rice and water in them, in which of the pots will rice cook faster? (1 mark) 

QUESTION 38
a) The speed of a wave propagating is 330 m/s in air at 0°C. If the frequency is 440 Hz, what is its wavelength? (1 mark)

b) A ship sends out a sound wave and receives an echo after 1 second. If the velocity of the sound in water is 1500 m/s, determine how deep is the water. (1 mark)

c) All AM radio stations are assigned frequencies in the range between 550 and 1600 Hz. The speed of propagation of radio waves is 3 x10!m/s . What wavelengths do these radio waves span? (2 marks)

d) Waves in a deep region of a ripple tank have a velocity of 6 cm/s and wavelength of 4 cm. They pass into a shallow region where their speed is 4cm/s.
i). Calculate the wavelength of the wave in the shallow region. (1 mark)
ii). Calculate the frequency of the waves in the deep region. (1 mark)
iii). Calculate the frequency of the waves in the shallow region (1 mark)

QUESTION 20
Which statement best explains the main difference between mechanical waves and electromagnetic waves?
A. Electromagnetic waves travel as fast as mechanical waves.
B. Electromagnetics waves have a source as mechanical waves do not.
C. Electromagnetic waves can travel through vacuum as mechanical wave do not.
D. Electromagnetic have a high frequency than mechanical waves.
E. Mechanical waves travel faster than electromagnetic waves.

QUESTION 21
The bending of waves around obstacles is called _____________.
A. reflection
B. diffraction
C. refraction
D. interference
E. destructive interference
​

QUESTION 23
The magnetic field lines of a wire carrying uniform current is
A.  circular centered about the wire.
B.  rectangular centered about the wire.
C.  square centered about the wire.
D.  straight and parallel to the wire.
E.  straight and perpendicular to the wire. 

QUESTION 25
A power grid line having a resistance of 2Ω is to be used to transmit 2000W of power. The power engineer has a choice of using current values from 1A – 10A. For minimum power loss which current should be used to transmit power?

A.  10 A
B.  1A
C.  2A
D.  5A
E.  7A

Note : Attempt the questions by commenting below. Then check your answers against the ones we provided below. 

QUESTION 1
Which instrument would be appropriate for measuring the thickness of an A4 sheet of paper?
A.    A Vernier Calliper
B.    A meter ruler
C.    A micrometer
D.    A top pan balance
E.    A 30 cm ruler

QUESTION 2
Which of the following combination of basic SI units is a joule (J)?
A.   kg ms-2 
B.   kg m-1 s-2 
C.   kg m-2 s-2
D.   kg m-1 s-1
E.   kg m-1s-2

QUESTION 3
A ball is thrown up in air and returns to the thrower. During its motion, the acceleration of the ball
A.    remains constant and directed upwards for all times.
B.    remains constant and directed downwards for all times.
C.    changes in magnitude and directed downwards for all times.
D.    changes in magnitude and directed upwards for all times.
E.    remains constant but directed upwards when the ball is moving up and is directed downwards when the ball is moving downwards.

QUESTION 4
The area under the velocity-time graph for an object moving with constant acceleration represents
A.   momentum.
B.   initial velocity.
C.   acceleration.
D.   final velocity.
E.   displacement.

QUESTION 5
A projectile is launched upwards at an angle less than 90°
, relative to the horizontal. During its motion, the
velocity in the horizontal direction
A.    changes.
B.    remains constant always.
C.     is zero at maximum height of the projectile.
D.    is always positive on the way up only.
E.     is always negative on the way down only. 

QUESTION 6
According to Newton’s second law of motion, force is directly proportional to rate of change of
A.    square of linear velocity.
B.    square of linear acceleration.
C.     linear velocity.
D.     linear momentum.
E.     linear acceleration. 

QUESTION 12
Which of the following description best suits a state of matter in a gaseous form?
A.   Strong bonds between their molecules making them very difficult to break. Have fixed shape and volume

B.  Having a fixed volume, but their shape is determined by the shape of the container holding them. They
have weak bonds between their molecules.

C. Virtually no bonds between their molecules. They have no fixed shapes and volume in the container they occupy.
D. The bonds between them is week, but have fixed volume and shape.

E. Virtually no bonds existing between their molecules. Spread into available space and their volume is
determined by the shape and size of the container holding them. 

QUESTION 14
Heat can be transmitted in three main ways, conduction, convection and radiation. Which of the following way(s) do not require a medium of heat transfer?
A.  Convection
B.  Conduction
C.  Radiation
D.  Radiation and Conduction
E.  Convection and Radiation

QUESTION 15
A change of state directly from a solid to a gas without going through a liquid state is called
A.  Condensation
B.  Vaporization
C.  Radiation
D.  Sublimation
E.  Ionization


Note: Make sure, you attempt the questions first before you view the Answers below.   Also see the remaining questions on the next post.