A car is moving with velocity v. It stops after applying breaks at a distance of 20 m. If the velocity of the car is doubled, then how much distance it will cover (travel) after applying breaks?
1. 40 m
2. 80 m
3. 160 m
4. 320 m
A body starts falling from height hh and if it travels a distance of h2 during the last second of motion, then the time of flight is (in seconds):
1. √2−1
2. 2+√2
3. √2+√3
4. √3+2
For a particle, displacement time relation is given by; t = √x + 3 . Its displacement, when its velocity is zero will be:
1. 2 m
2. 4 m
3. 0 m
4. none of the above
A particle starts from rest with constant acceleration. The ratio of space-average velocity to the time-average velocity is:
where time-average velocity and space-average velocity, respectively, are defined as follows:
<v>time = ∫vdt∫dt
<v>space = ∫vds∫ds
1. | 12 | 2. | 34 |
3. | 43 | 4. | 32 |
The motion of a particle is given by the equation S=(3t3+7t2+14t+8)m, The value of the acceleration of the particle at t=1 s is:
1. | 10 m/s2 | 2. | 32 m/s2 |
3. | 23 m/s2 | 4. | 16 m/s2 |
A particle is thrown vertically upward. Its velocity at half its height is 10 m/s. Then the maximum height attained by it is: (Assume, g= 10 m/s2)
1. 8 m
2. 20 m
3. 10 m
4. 16 m
If a ball is thrown vertically upwards with speed u, the distance covered during the last t seconds of its ascent is:
1. ut
2. 12gt2
3. ut−12gt2
4. (u+gt)t
A man throws some balls with the same speed vertically upwards one after the other at an interval of 2 seconds. What should be the speed of the throw so that more than two balls are in the sky at any time? (Given g=9.8 m/s2)
1. | 19.6 m/s | More than
2. | 9.8 m/s | At least
3. | 19.6 m/s | Any speed less than
4. | 19.6 m/s | Only with a speed of
A ball of mass 2 kg and another of mass 4 kg are dropped together from a 60 feet tall building. After a fall of 30 feet each towards the earth, their respective kinetic energies will be in the ratio of:
1. 1: 4
2. 1: 2
3. 1: √2
4. √2 :1
The displacement x of a particle varies with time t as x=ae−αt+beβt, where a, b, α, and β are positive constants. The velocity of the particle will:
1. | α and β. | be independent of
2. | go on increasing with time. |
3. | α=β. | drop to zero when
4. | go on decreasing with time. |