A body is executing uniform circular motion in a circle of radius 100 m at speed 10 m/s. Acceleration of the body is :
(1) Zero
(2) 2
(3) 1
(4) 5
A particle started revolving from rest with a constant angular acceleration in a circular path of radius r. If centripetal acceleration becomes numerically equal to tangential acceleration at time t, then t is equal to:
1.
2.
3.
4.
Balls A and B are thrown simultaneously from two points lying on the same horizontal plane separated by a distance 120 m. Path of A w.rt. B is
(1) Parabola
(2) Hyperbola
(3) Circle
(4) Straight line
Which of the following is the angle between velocity and acceleration of a body in uniform circular motion?
1. \(30^\circ\)
2. \(45^\circ\)
3. \(60^\circ\)
4. \(90^\circ\)
A man wants to cross a river of width 500 m in the minimum distance. The rowing speed of man relative to water is 3 km/h and river flows with speed 2 km/h. The time taken by the man to cross the river
(1) 2 minute
(2) 6 minute
(3) 2 minute
(4) 6 minute
A person is rotating in a horizontal circle of radius 7 m. Find the period of rotation for which the acceleration is equal to 3g.
(1) 2.6 s
(2) 2.8 s
(3) 3.1 s
(4) 4.3 s
A man can row a boat with a speed of \(10~\text{kmph}\) in still water. The river flows at \(6~\text{kmph}.\) If he crosses the river from one bank to the other along the shortest possible path, the time taken to cross the river of width \(1~\text{km}\) is:
1. \(\frac{1}{8}~\text{hr}\)
2. \(\frac{1}{4}~\text{hr}\)
3. \(\frac{1}{2}~\text{hr}\)
4. \(1~\text{hr}\)
A bus is going to the North at a speed of \(30\) kmph. It makes a \(90^{\circ}\) left turn without changing the speed. The change in the velocity of the bus is:
1. | \(30~\text{kmph}\) towards \(\mathrm{W}\) |
2. | \(30~\text{kmph}\) towards \(\mathrm{S\text-W}\) |
3. | \(42.4~\text{kmph}\) towards \(\mathrm{S\text-W}\) |
4. | \(42.4~\text{kmph}\) towards \(\mathrm{N\text-W}\) |
Two bullets are fired simultaneously horizontally and at different speeds from the same place. Which bullet will hit the ground first? (Air resistance is neglected)
1. | The faster one |
2. | The slower one |
3. | Depends on masses |
4. | Both will reach simultaneously |
A pilot is supposed to fly east from A to B and back again A due west. If the wind is blowing due south, find time for the round trip, if AB = l. The velocity of the plane in the air is v and the velocity of wind is u.
1.
2.
3.
4.