Motion in a Str...

An automobile travelling with a speed of 60 kmh^-1, can brake to stop within a distance of 20 m. If the car is going twice as fast, i.e. 120 kmh^-1, the stopping distance will be

A particle located at x = 0 at time t = 0, starts moving along the positive x–direction with a velocity v that varies as v = α√x. The displacement of the particle varies with time as

A metro train starts from rest and in 5 s achieves 108 kmh^-1. After that it moves with constant velocity and comes to rest after travelling 45 m with uniform retardation. If total distance travelled is 395 m, find total time of travelling.

A bullet moving with a speed of 100 ms^-1 can just penetrate two planks of equal thickness. Then, the number of such planks penetrated by the same bullet when the speed is doubled will be

A balloon is rising vertically up with a velocity of 29 ms^-1. A stone is dropped from it and it reaches the ground in 10 s. The height of the balloon when the stone was dropped from it is ( take,g = 9.8 ms^-2 )

From the top of a tower, two stones, whose masses are in the ratio 1 : 2 are thrown on straight up with an initial speed u and the second straight down with the same speed u. Then, neglecting air resistance

From a balloon rising vertically upwards 5 ms^-1 at stone is thrown up at 10 ms^-1 relative to the balloon. Its velocity w.r.t. ground after 2 s is (assume, g = 10 ms^-2)

A balloon going upward with a velocity of 12 ms^-1 is at a height of 65 m from the earth's surface at any instant. Exactly at this instant a ball drops from it. How much time will the ball take in reaching the surface of the earth? (Take, g = 10 ms^-2)