1. A body starts from rest and moves with a uniform acceleration of 3 m/s². The distance it covers in the first 2 s is:
- 9 m
- 3 m
- 12 m
- 6 m
Show answer and explanation
Answer: (D) 6 m
Starting from rest, u = 0, so s = ut + ½at² = 0 + ½ × 3 × 2² = 6 m.
90 questions on this topic of Kinematics (NEET 2027 syllabus). Here are 12; tap one to see its answer and explanation.
Free with a Google sign-in; NEET Daily needs no sign-in at all.
Answer: (D) 6 m
Starting from rest, u = 0, so s = ut + ½at² = 0 + ½ × 3 × 2² = 6 m.
Answer: (C) 90 m
Convert: v = 108/3.6 = 30 m/s. Using v² = u² − 2as with final speed 0: s = u²/2a = 30²/10 = 90 m.
Answer: (A) 40 m/s
For motion with uniform acceleration α followed immediately by deceleration β to rest, total distance S = v²/(2α) + v²/(2β) = (v²/2) × (1/α + 1/β) = (v²/2) × (1/2 + 1/4) = (v²/2) × (3/4) = 3v²/8. Given S = 600 m, we have 3v²/8 = 600 => v² = (600 × 8)/3 = 1600 => v = 40 m/s.
Answer: (A) 39.1 m
Convert: v = 90/3.6 = 25 m/s. Using v² = u² − 2as with final speed 0: s = u²/2a = 25²/16 = 39.1 m.
Answer: (D) 25 m
Starting from rest, u = 0, so s = ut + ½at² = 0 + ½ × 2 × 5² = 25 m.
Answer: (C) 2 m
Acceleration can be expressed as a = v(dv/dx). Given v(dv/dx) = -2v, so dv/dx = -2 (for v ≠ 0), which means dv = -2 dx. Integrating both sides: ∫ dv from 5 to 1 = -2 ∫ dx from 0 to s. Thus, 1 - 5 = -2s, giving -4 = -2s, or s = 2 m.
Answer: (C) 56.3 m
Convert: v = 54/3.6 = 15 m/s. Using v² = u² − 2as with final speed 0: s = u²/2a = 15²/4 = 56.3 m.
Answer: (A) +6 m/s²
Velocity is v = dx/dt = 6t² - 18t + 12 = 6(t - 1)(t - 2). Thus, v = 0 at t = 1 s and t = 2 s. The second time is t = 2 s. Acceleration is a = dv/dt = 12t - 18. At t = 2 s, a = 12(2) - 18 = +6 m/s².
Answer: (B) 37.5 m
Starting from rest, u = 0, so s = ut + ½at² = 0 + ½ × 3 × 5² = 37.5 m.
Answer: (C) 90 m
Starting from rest, u = 0, so s = ut + ½at² = 0 + ½ × 5 × 6² = 90 m.
Answer: (B) Statement I is correct but Statement II is incorrect.
Velocity is a vector quantity (magnitude and direction), whereas speed is its magnitude. Direction can change while magnitude (speed) remains constant, as in uniform circular motion, so Statement I is correct. However, if speed changes, the magnitude of velocity changes, so velocity cannot remain constant; Statement II is incorrect.
Answer: (B) 128 m
Starting from rest, u = 0, so s = ut + ½at² = 0 + ½ × 4 × 8² = 128 m.