WAEC Physics 2000 Past Questions

Practice each question, then open it to see the full details.

Question 11

(a)(i) Define the term linear momentum.

(ii) State the law of conservation of linear momentum.

(b) A ball P of mass 0.25 kg, loses one-third of its velocity when it makes a head on collision with an identical ball Q at rest. After the collision, Q moves off with a speed of 2ms\(^{-1}\) in the original direction of P. Calculate the initial velocity of R

(c)(i) State Newton's second law of motion.

(ii) Show that F = ma where F is the magnitude of the force acting on a body of mass m to give it an acceleration of magnitude a.

(iii) The engine of a vehicle moves it forward with a force of 9600 N against a resistive force of 2200 N. If the mass of the vehicle is 3400 kg, calculate the acceleration produced.

Theory
Question 12

(a)(i) Mention two modes of heat transfer other than convection.

(ii) Explain land and sea breezes.

(b) An iron rod of length 30cm is heated through 50 kelvin. Calculate its increase in length. (linear expansivity of iron = 1.2 x 10\(^{-5}\)K\(^{-1}\)

(c) An electric heater immersed in some water raises the temperature of the water from 40°C to 100°C in 6 minutes. After another 25 minutes, it is noticed that half the water has boiled away. Neglecting heat losses to the surrounding, calculate the specific latent heat of vaporisation of water.

Theory
Question 13
An inelastic collision takes place between ball of known masses, just before the collision one of the ball is moving with a known velocity while the other is stationary. Which of the following physical quantities can be determined from the information given?
  • A.speed of each of the ball after collision
  • B.kinetic energy of each ball after collision
  • C.total momentum of the ball after collision
  • D.total momentum of the two ball after collision
  • E.mutual forces excerted by the balls
Objective
Question 13

(a)(i) State the laws of refraction of light.

(ii) Describe an experiment to determine the refractive index, n, of the material of an equilaleral triangular glass prism using the minimum deviation method.

(b) A rectangular glass prism of thickness 12cm is placed on a mark on a piece of paper resting on a horizontal bench:

(i) Draw a ray diagram to show the apparent position of the mark in the glass prism.

(ii) If the refractive-index of the material of the prism is 1.5, calculate the apparent displacement of the mark.

Theory
Question 14

(a) Define the following terms:

(i) Electric field intensity

(ii) Electric potential

(b) The diagram below illustrates two collinear electric charges of magnitudes + Q and -Q. The charges are equidistant from a point P at which a rest charge is placed.

Copy the diagram and use arrows to indicate, from the point P, the direction of the;

(i) electric force F\(_1\) due to + Q.

(ii) electric force F\(_2\) due to -Q.

(iii) electric field intensity E.

 

(c) What is meant by dielectric substance?

(ii) List the factors which determine the capacitance of a parallel plate capacitor and state the effect each of them has on the capacitance.The diagram above represents a section of a circuit. Calculate the effective capacitance in the section.

(iii) 

The diagram above represents a section of a circuit. Calculate the effective capacitance in the section.

 

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Theory
Question 15

(a)(1) State the energy transformations which take place during the operation of a modern x-ray tube.
(ii) Distinguish between hard and soft x-rays.

(iii) State three uses of x-rays.

(iv) Mention one hazard of over-exposure to x-rays in a radiological laboratory, and indicate any two safety precautions.

(b) A possible fusion reaction is \(^2_1 H + ^2_1 H \to ^3_1H + ^1_1H + Q\)

where Q is the energy released as a result of the reaction. If Q = 4.03 MeV, calculate the atomic mass of \(^3_1H\) in atomic mass units. (\(^2_1 H = 2.01410 U; ^1_1H = 1.00783 U; 1U = 931 MeV\))

Theory