EASY
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A boy drops a ball from the top of a building consisting of several floors. Each floor has the same height. The ball covers one floor from the top in one second. The number of floors, the ball will cover in three seconds is

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Important Questions on Measurements and Motion

HARD
In a car race, two cars start with velocities u1 and u2 and travel along a straight line with accelerations α and β respectively. If both reach the finish line at the same time then range of the race is
EASY
An object is thrown vertically with a velocity u. The velocity with which it strikes the ground on its return is
MEDIUM
A ball is projected vertically up from ground. Boy 'A' standing at the window of first floor of a nearby building observes that the time interval between the ball crossing him while going up and the ball crossing him while going down is 2 s. Another boy B standing on the second floor notices the time interval between the ball passing him twice, during up and down motion is 1 s. Calculate the difference between the vertical positions of boy B and boy A. (Assume g=10 m s-2)
HARD
Two particles A and B move from rest along a straight line with constant accelerations f and h, respectively. If A takes m seconds more than B and describes n units more than that of B acquiring the same speed, then
HARD
A stone thrown down with a seed u takes a time t1 to reach the ground, while another stone, thrown upwards from the same point with the same speed, takes time t2 . The maximum height the second stone reaches from the ground is
MEDIUM
A particle is projected vertically upwards. If it has to stay above the ground for 12 sec, then
HARD
A helicopter rises from rest on the ground vertically upwards with a constant acceleration g. A food packet is dropped from the helicopter when it is at a height h. The time taken by the packet to reach the ground is close to [g is the acceleration due to gravity]:
MEDIUM
A ball is dropped from the top of the building 100 m high. Simultaneously, another ball is thrown upwards from the bottom of the building with such a velocity that the balls collide exactly mid-way. What is the speed in m s-1 with which the second ball is thrown? (Take g=10 m s-2 )
EASY

A particle starts from origin O from rest and moves with a uniform acceleration along the positive  x-axis . Identify all figures that correctly represent the motion qualitatively.
( a= acceleration, v= velocity, x=  dispalcement, t= time)
A Question Image
B Question Image
(C) Question Image
(D) Question Image

MEDIUM
An object with mass 5 kg is acted upon by a force, F=(-3i^+4j^)N. If its initial velocity at t=0 is v=(6i^-12j^) ms-1, the time at which it will just have a velocity along y-axis is
EASY
A particle has initial velocity 2i^+3j^ and acceleration 0.3i^+0.2j^. The magnitude of velocity after 10 seconds will be
EASY
In a car race on straight road, car A takes a time t less than car B at the finish and passes finishing point with a speed v more than that of car B. Both the cars start from rest and travel with constant acceleration a1 and a2  respectively. Then v is equal to:
EASY
A ball is dropped from a height of 19.6 m. The distance covered by it in the last second is
HARD
From the top of a tower of height H, a body is thrown vertically upwards with a speed u. Time taken by the body to reach the ground is 3 times the time taken by it to reach the highest point in its path. Then, the speed u is
EASY
A body moving with uniform acceleration 6 m/s2 starts from rest. The distance covered by it in 4th  second will be
EASY
A boy pushes a box of mass 2 kg with a force F=20i^+10j^N on a frictionless surface. If the box was initially at rest, then _______ m is displacement along the x-axis after 10 s
HARD
An engine of a train, moving with uniform acceleration, passes the signal-post with velocity u and the last compartment with velocity v. The velocity with which middle point of the train passes the signal post is :
MEDIUM
A ship of mass 2×107kg initially at rest is pulled by a force of 5×105N, through a distance of 2m. Assuming that the resistance due to water is negligible, the speed of the ship is
HARD
A parachutist with total weight 75 kg drops vertically onto a sandy ground with a speed of 2 m s-1 and comes to a halt over a distance of 0.25 m. The average force from the ground on her is close to-
HARD
A piece of wood of mass 0.03 kg is dropped from the top of a 100 m height building. At the same time, a bullet of mass 0.02 kg is fired vertically upward, with a velocity 100 m s-1, from the ground. The bullet gets embedded in the wood. Then the maximum height to which the combined system reaches above the top of the building before falling below is: g=10 m s-2