A boat is sent across a river with a velocity of 8 km h-1. If the resultant velocity of boat is 10 km h-1 , then velocity of river is
12.8 km h-1
6 km h-1
8 km h-1
10 km h-1
A train of 150 m length is going towards north direction at a speed of 10m/s. A parrot flies at the speed of 5 m/s towards south direction parallel to the railways track.The time taken by the parrot to cross the train is
m1: m2 : m3
m1 : 2m2 : 3m3
1 : 1 : 1
The angle between the two vectors will be
0°
45°
90°
180°
zero acceleration
A body is thrown vertically upwards from the ground. It reaches a maximum height of 20 m in 5s. After what time it will reach the ground from its maximum height position?
The ratios of the distance covered by a freely falling particle, starting from rest in the first, second, third ... nth seconds of its motion
Form the series corresponding to the squares of the first n natural numbers
Form an A.P.
Form a series corresponding to the difference of the squares of the successive natural numbers
Both choices (b) and (c) are correct
A body falling from rest describes distances S1, S2 and S3 in the first, second and third seconds of its fall. The ratio of S1 : S2 : S3 is
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,
Ball P reaches the ground first
Ball Q reaches the ground first
Both the balls reach the ground at the same time
Respective masses of the two balls will decide the time
If a car at rest accelerates uniformly to a speed of 144 km/h in 20 s, it covers a distance of
