First Term Examination
Class : SSS 2
Subject : Physics
Duration : 1 Hours 30 Minutes
Section A : Objective Questions
1. Determine the distance between the points S (0, 2, 0) and T (3, 2, 1). (a) 3.0 (b) 3.2 (c) 4.0 (d) 4.2 (e) 5.0
2. The bearing 230°×represents (a) N 50°E (b) N 50°W (c) S 50°E (d) S 50° W (e) Ń 80° E
3. Which of the following is not a scalar quantity? (a) density (b) weight (c) speed. (d) mass (e) temperature
4. A boy pulls his toy in a smooth horizontal surface with a rope inclined at 60°×to the horizontal. If the effective force pulling the toy along the horizontal surface is 5N. Calculate the tension on the rope. (a) 2.50N (b) 4.33N (c) 5.00N (d) 8.66N (e) 10.0 N
5. The maximum height of a projectile projected with an angle of Θ° to the horizontal and an initial velocity of U is given by : (a) Usin / g (b) (c) (d) (e)
6. A stone is projected at an angle of 60° and initial velocity of 20ms-1. Determine the time of flight. (a) 33.6 s (b) 3.46 s (c) 1.73 s (d) 6.92 s (e) 17.3 s
7. For a projectile the maximum range is obtained when the angle of projection is (a) 60° (b) 30° (c) 45° (d) 75° (e) 90°
8. What is the angular speed of a body vibration at 59 cycles per second? (a) 200π rads¯¹ (b) 100π rads¯¹ (c) 50π rads¯¹(d) 400π rads¯¹ (e) 0.01π rads¯¹
9. The vibration resulting from the action of an external period force on the motion of a body is called __________. (a) forced vibration (b) damped vibration (c) natural vibration (d) compound vibration (e) simisoidal vibration
10. Which of the following correctly gives the relationship between linear speed V and angular speed W of a body moving with uniformly in a circle of radius r? (a) V = wr (b) V = w²r (c) V = wr² (d) v² = wr (e) V = w/r
11. A constant force of 5N acts for 5swconds on a mass of 5kg initially at rest. Calculate the final momentum. (a) 125kgms-¹ (b) 25kgms-¹ (c) 15kgms-¹ (d) 5kgms-¹ (e) 0 kgms-¹
12. A ball of mass 0.5kg moving at 10ms-¹ collides with another ball of equal mass at rest. If the two ball moves off together after the impact, calculate their common velocity. (a) 0.2ms-¹ (b) 0.5ms-¹ (c) 5.0ms-¹ (d) 10ms-¹ (e) 20ms-¹
13. A plane inclined at an angle of 30° to the horizontal has an efficiency of 60%. The force parallel to the plane required to push a little ad of 120N uniformly up the plane is (a) 60N (b) 100N (c) 120N (d) 200N (e) 240N
14. Which of the following is not an example of levers of the first order? (a) crowbar (b) nutcracker (c) scissors (d) plier (e) claw hammer
15. A machine with a velocity ratio of 30 moves a load of 3000N when an effort of 200N is applied. The efficiency of the machine is (a) 30% (b) 50% (c) 60% (d) 25% (e) 75%
16. The forces A and B act at a point at right angles if their resultant is 50N and their sum is 70N, their magnitudes are : (a) 50N and 20N (b) 20N and 40N (c) 40N and 30N (d) 60N and 10N (e) 45N and 25N
17. The S. I unit of the moment of a force is ___________. (a) kgm (b) Nm (c) Jm (d) Nm-¹ (e) Jm-¹
18. A mango fruit drops to the ground from the top of its tree which is 5m high, how long does it take to reach the ground? (a) 1.0s (b) 2.0s (c) 3.0s (d) 5s (e) 0.5s
19. Calculate the height from which a body is released from rest if it’s velocity just before hitting the ground is 20ms-¹. (a) 15m (b) 45m (c) 60m (d) 90m (e) 75m
20. A body starts from rest and moves with constant acceleration. Which of the following quantities varies / vary linearly with the square of the time? (I) Velocity (II) Displacement (III) Momentum. (a) I only (b) II only (c) III only (d) I and II only (e) II and III only.
Section B : Theory
Answer three (3) questions in all. Question 1 is compulsory.
1. An object is acted upon by two forces of 5N and 12N. Calculate the resultant of the two forces if :
(a) The forces act perpendicular to each other
(b) The two forces act at an angle of 40° to each other.
(c) The two forces act at an angle of 125° to each other.
2a. State the principle of conservation of linear momentum.
(b) State Newton’s laws of motion.
(c) A ball P of mass 0.25kg, losses one-third of its velocity when it makes a head on collision with an identical ball Q at rest. After collision, Q moves off with a speed of 2ms-¹ in the original direction of P. Calculate the initial velocity of P.
3a. Define Projectile and give five applications of projectiles.
(b) A body is projected from the ground at an angle Q to the horizontal with a velocity of 35m/s. It reached a maximum height of 11.65m. Calculate :
i. The value of Q;
ii. The time taken to strike the ground;
iii. The range covered
4a. Define Simple Harmonic Motion (SHM)
(b) A body moving with SHM has amplitude of 10cm and a frequency of 100Hz. Find :
(i.) The period of oscillation
(ii.) The acceleration at the maximum displacement
(iii.) The velocity at the Centre of motion
5. Explain with the aid of a diagram, what is meant by the moment of a force about a point.