ECAT — Engineering College Admission Test (UET)
Take the ECAT Physics — Motion, Force and Momentum (Set 3): 30 multiple-choice questions (40 minutes) with instant scoring and a full answer review.…
What this test covers
The first 5 questions of this test, with the correct answer and explanation.
Q1. A car travelling at 20 m/s is brought to rest uniformly in 40 m. The magnitude of its deceleration is
Answer: D. 5 m/s²
Explanation: 0 = 20² − 2a(40) gives a = 400/80 = 5 m/s².
Q2. A stone is thrown vertically upward at 30 m/s. The maximum height reached is
Answer: B. 45 m
Explanation: h = u²/2g = 900/20 = 45 m.
Q3. The stone in the previous situation (thrown upward at 30 m/s, g = 10 m/s²) returns to the thrower’s hand after
Answer: D. 6 s
Explanation: T = 2u/g = 60/10 = 6 s.
Q4. A ball is kicked horizontally at 15 m/s from the top of an 80 m cliff. It lands at a horizontal distance of
Answer: A. 60 m
Explanation: t = √(2h/g) = √16 = 4 s; range = 15 × 4 = 60 m.
Q5. A projectile fired at 40 m/s at 30° to the horizontal has the same range as one fired at the same speed at
Answer: A. 60°
Explanation: Complementary launch angles (30° + 60° = 90°) give equal ranges since R ∝ sin2θ.
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Q6. A projectile is launched at 40 m/s at 30° above the horizontal. Its maximum height is
Q7. A body starts from rest and accelerates uniformly at 2 m/s² for 5 s, then moves at constant velocity for 10 s. The total distance covered is
Q8. A car covers the first half of a journey at 30 km/h and the second half at 60 km/h. Its average speed for the whole journey is
Q9. A swimmer who can swim at 5 m/s in still water heads straight across a river flowing at 3 m/s. His resultant speed relative to the bank is
Q10. A 60 kg person stands on a scale in a lift accelerating upward at 2 m/s². The scale reads (g = 10 m/s²)
Q11. A 60 kg person stands on a scale in a lift whose cable has snapped and the lift falls freely. The scale reads
Q12. A smooth incline makes 30° with the horizontal. A block released on it accelerates down the slope at
Q13. A block slides down a 30° incline with coefficient of kinetic friction 0.25. Taking √3 ≈ 1.73, its acceleration is approximately
Q14. Masses of 3 kg and 5 kg hang over a light frictionless pulley. The acceleration of the system is
Q15. For the 3 kg and 5 kg masses over a light frictionless pulley (g = 10 m/s²), the tension in the string is
Q16. A 4 kg gun fires a 20 g bullet at 400 m/s. The recoil speed of the gun is
Q17. A 2 kg trolley moving at 6 m/s collides with a stationary 4 kg trolley and they stick together. Their common velocity is
Q18. In the same collision (2 kg at 6 m/s striking a stationary 4 kg and sticking), the kinetic energy lost is
Q19. A 0.5 kg ball moving at 4 m/s collides head-on elastically with a stationary 0.5 kg ball. Afterwards the first ball has a velocity of
Q20. A 0.2 kg ball moving at 10 m/s hits a wall and rebounds at 6 m/s along the same line. The magnitude of the impulse on the ball is
Q21. A force rising uniformly from 0 to 20 N acts for 4 s on a body, as the force–time graph is a straight line from the origin. The impulse delivered is
Q22. Two bodies of masses m and 4m have equal kinetic energies. The ratio of their momenta (lighter : heavier) is
Q23. A body dropped from rest falls through what distance during the third second of its fall (g = 10 m/s²)?
Q24. A passenger in a bus lurches forward when the bus brakes suddenly. This is best explained by
Q25. A bat hits a 0.15 kg ball initially at rest, giving it a speed of 30 m/s. If the contact lasts 0.01 s the average force is
Q26. A rocket expels 500 kg of gas per second at an exhaust speed of 2000 m/s relative to the rocket. The thrust is
Q27. Blocks of 2 kg and 3 kg are in contact on a smooth floor. A 20 N horizontal force pushes the 2 kg block, which pushes the 3 kg block. The contact force between the blocks is
Q28. A runner completes 1.5 laps of a circular track of radius 100 m, starting at a point P. The magnitude of the displacement from P is
Q29. Stone A is dropped from rest from a tower and stone B is thrown downward at 10 m/s from the same height at the same time. After 2 s the gap between them (g = 10 m/s²) is
Q30. A shell of mass 3 kg at rest explodes into two parts of 1 kg and 2 kg. If the 1 kg part moves off at 6 m/s, the speed of the 2 kg part is