The gravity in space is given by . Two particles are simultaneously projected with velocity and . Then, the ratio of their times of flight
1. 1:1
2. 1:2
3. 2:1
4. none
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 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 east and a car is along north, both with same speed. The observed direction of car to the passenger in 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.
3.
4.
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.
2.
3.
4.
An aeroplane is moving with a velocity \(u\). It drops a packet from a height \(h\). The time \(t\) taken by the packet in reaching the ground will be:
1. \(
\sqrt{\left(\frac{2 g}{h}\right)}
\)
2. \( \sqrt{\left(\frac{2 u}{g}\right)}
\)
3. \( \sqrt{\left(\frac{h}{2 g}\right)}
\)
4. \( \sqrt{\left(\frac{2 h}{g}\right)}\)
An aeroplane is moving with horizontal velocity u at height h. The velocity of a packet dropped from it on the earth's surface will be (g is acceleration due to gravity)
(1)
(2)
(3) 2 gh
(4)