A man rides a bicycle with a speed of 17.32 ms-1 East- West direction. If the rain falls vertically with a speed of 10 ms-1, then the direction in which he must hold his umbrella is
30° with the vertical towards East
60° with the vertical towards West
30° with the vertical towards West
60° with the vertical towards East
From a balloon moving upwards with a velocity of12 ms-1, a packet is released when it is at a height of 65 m from the ground. The time taken by it to reach the ground is (take, g = 10 ms-2)
5 s
8 s
4 s
7 s
A bus is moving with a velocity of 10 ms-1 on a straight road. A scootorist wishes to overtake the bus in one minute. If the bus is at a distance of 1.2 km ahead, then the velocity with which he has to chase the bus is
20 ms-1
25 ms-1
30 ms-1
40 ms-1
If the displacement of a body varies as the square of elapsed time, then its
velocity is constant
velocity varies non-uniformly
acceleration is constant
acceleration changes continuously
A ball dropped from a point A falls down vertically to C, through the mid-point B. The descending time from A to B and that from A to C are in the ratio
1 : 1
1 : 2
1 : 3
The time required to stop a car of mass 800 kg, moving at a speed of 20ms-1 over a distance of 25 m is
2 s
2.5 s
4 s
4.5 s
B.
2.5 s
Given, u = 0 ms-1 , v = 20 ms-1
Mass of car = 800 Kg , s = 25 m
We know that, distance covered,
The ratio of distance traversed in successive intervals of time when a body falls freely under gravity from certain height is
1 : 2 : 3
1 : 5 : 9
1 : 3 : 5
A particle starting with certain initial velocity and uniform acceleration covers a distance of 12 m in first 3 s and a distance of 30 m in next 3 s. The initial velocity of the particle is
3 ms-1
2.5 ms-1
1 ms-1
1.5 ms-1