A body is projected with a velocity u with an angle of projection θ. The change in velocity after the time (t) from the time of projection will be:
1. | gt | 2. | 12gt2 |
3. | usinθ | 4. | ucosθ |
What determines the nature of the path followed by the particle?
1. Speed only
2. Velocity only
3. Acceleration only
4. None of these
A boat is sent across a river in perpendicular direction with a velocity of 8 km/hr. If the resultant velocity of boat is 10 km/hr, then velocity of the river is :
1. 10 km/hr
2. 8 km/hr
3. 6 km/hr
4. 4 km/hr
A boat is moving with velocity of 3ˆi+4ˆj in river and water is moving with a velocity of −3ˆi−4ˆj with respect to ground. Relative velocity of boat with respect to water is:
1. −6ˆi−8ˆj
2. 6ˆi+8ˆj
3. 8ˆj
4. 6ˆi
A boat moves with a speed of 5 km/h relative to water in a river flowing with a speed of 3 km/h and having a width of 1 km. The minimum time taken around a round trip(returning to the initial point) is:
1. 5 min
2. 60 min
3. 20 min
4. 30 min
A river is flowing from W to E with a speed of 5 m/min. A man can swim in still water with a velocity 10 m/min. In which direction should the man swim so as to take the shortest possible path to go to the south.
1. 30° with downstream
2. 60° with downstream
3. 120° with downstream
4. South
A train is moving towards the east and a car is along the north at the same speed. The observed direction of the car to the passenger on the train is:
1. East-north direction
2. West-north direction
3. South-east direction
4. None of these
A ball P is dropped vertically and another ball Q is thrown horizontally from the same height and at the same time. If air resistance is neglected, then
1. Ball P reaches the ground first
2. Ball Q reaches the ground first
3. Both reach the ground at the same time
4. The respective masses of the two balls will decide the time
A frictionless wire AB is fixed on a sphere of radius R. A very small spherical ball slips on this wire. The time taken by this ball to slip from A to B is:
1. 2√gRgcosθ
2. 2√gR.cosθg
3. 2√Rg
4. gR√gcosθ
A body is slipping from an inclined plane of height h and length l. If the angle of inclination is θ, the time taken by the body to come from the top to the bottom of this inclined plane is:
1. √2hg
2. √2lg
3. 1sinθ√2hg
4. sinθ√2hg