| ⇦ | 
| ⇨ |
A car is moving with uniform acceleration. It covers 200 m in 2 sec and 220 m in next 4 sec. The velocity of car at the end of 7th second from start is
Options
(a) 1 m/s
(b) 0.1 m/s
(c) 10 m/s
(d) 20 m/s
Correct Answer:
10 m/s
Explanation:
For first 2 second
S = 2u +1/2α (2)²
200 = 2u + 2α
or u + α = 100 …(i)
For first 2 + 4 = 6 second
S = 200 + 220 = 420 m
420 = 6u + 36/2 α
420 = 6u + 18α ⇒ 420 = 6(u + 3α)
u + 3α = 420/6 = 70 …(ii)
Solving equation (i) and (ii)
α = -15 m/sec²
This is the retardation.
Using these formula V=ut+1/2 αt²
200 = u+1/2 (-15)(2)²
u = 115
Hence velocity after 7 second is
V = u+αt
= 115 + (–15) x 7
= 10 m/sec.
Related Questions: - For a given velocity, a projectile has the same range R for two angles of projection.
- If μᵥ=1.5230 and μʀ=15.145, then dispersive power of crown glass is
- When the speed of electron beam used in Young’s double slit experiment is increased,
- In atom bomb, the reaction which occurs is
- An observer moving away from a stationary source. The observed frequency is half
Topics: Motion in Straight Line
(93)
Subject: Physics
(2479)
Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score
- For a given velocity, a projectile has the same range R for two angles of projection.
- If μᵥ=1.5230 and μʀ=15.145, then dispersive power of crown glass is
- When the speed of electron beam used in Young’s double slit experiment is increased,
- In atom bomb, the reaction which occurs is
- An observer moving away from a stationary source. The observed frequency is half
Topics: Motion in Straight Line (93)
Subject: Physics (2479)
Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score
18000+ students are using NEETLab to improve their score. What about you?
Solve Previous Year MCQs, Mock Tests, Topicwise Practice Tests, Identify Weak Topics, Formula Flash cards and much more is available in NEETLab Android App to improve your NEET score.
Share this page with your friends
Leave a Reply