A particle moves along a straight line such that its displacement at any time \(t\) is given by \(S = t^{3} - 6 t^{2} + 3 t + 4\) metres. The velocity when the acceleration is zero is:
1. | \(4\) ms-1 | 2. | \(-12\) ms−1 |
3. | \(42\) ms−1 | 4. | \(-9\) ms−1 |
If a body starts from rest and travels 120 cm in the 6th second, then what is the acceleration
1. 0.20 m/s2
2. 0.027 m/s2
3. 0.218 m/s2
4. 0.03 m/s2
If a car at rest accelerates uniformly to a speed of 144 km/h in 20 s. Then it covers a distance of
1. 20 m
2. 400 m
3. 1440 m
4. 2880 m
The position \(x\) of a particle varies with time \(t\) as \(x=at^2-bt^3\). The acceleration of the particle will be zero at time \(t\) equal to:
1. | \(\dfrac{a}{b}\) | 2. | \(\dfrac{2a}{3b}\) |
3. | \(\dfrac{a}{3b}\) | 4. | zero |
If a train travelling at 72 kmph is to be brought to rest in a distance of 200 metres, then its retardation should be
1. 20 ms–2
2. 10 ms–2
3. 2 ms–2
4.1 ms–2
The displacement of a particle starting from rest (at t = 0) is given by . The time in seconds at which the particle will attain zero velocity again, is
1. 2
2. 4
3. 6
4. 8
Two cars A and B are at rest at the same point initially. If A starts with uniform velocity of 40 m/sec and B starts in the same direction with a constant acceleration of 4 m/s2, then B will catch A after how much time?
1. 10 sec
2. 20 sec
3. 30 sec
4. 35 sec
The motion of a particle is described by the equation where a = 15 cm and b = 3 cm/s2. Its instantaneous velocity at time 3 sec will be
1. 36 cm/sec
2. 18 cm/sec
3. 16 cm/sec
4. 32 cm/sec
A body is moving according to the equation where x = displacement and a, b and c are constants. The acceleration of the body is
1.
2.
3.
4.
A particle travels 10 m in first 5 sec and 10m in the next 3 sec. Assuming constant acceleration what is the distance travelled in next 2 sec ?
1. 8.3 m
2. 9.3 m
3. 10.3 m
4. None of above