Motion Test - 3...

A body projected up with a velocity $$u$$ reaches maximum height $$h$$. To reach double the height, it must be projected up with a velocity of:

Two bodies are projected simultaneously with the same speed of $$19.6 \;ms^{-1}$$ from the top of a tower, one vertically upwards and the other vertically downwards. As they reach the ground, the time gap is:

Two balls are dropped to the ground from different heights. One ball is dropped $$2\ s$$ after the other but both of them strike the ground simultaneously $$5\ s$$ after the first is dropped. The difference in the heights, when they are dropped is ($$g=10\  m/s^2$$)

A body is thrown vertically up with certain velocity. If $$h$$ is the maximum height reached by it, its position when its velocity reduces to $$(1/3)^{rd}$$ of its velocity of projection is at

A ball is dropped from the top of a building. The ball takes $$0.5$$ s to fall past the window $$3$$ m in length at certain distance from the top of the building.  ($$g=10\;ms^{-2}$$)
Speed of the ball as it crosses the top edge of the window is 

A person standing on the edge of a well throws a stone vertically upwards with an initial velocity $$5ms^{-1}$$. The stone goes up, comes down and falls in the well making a sound. If the person hears the sound 3 second after throwing, then the depth of water is (neglect time travel for the sound and take $$g = 10ms^{-2}$$):

A body released from a height falls freely towards the earth. Another body is released from the same height exactly a second later. Then the separation between the two bodies two seconds after the release of the second body is

A stone is dropped from a balloon at an altitude of $$280\ m$$. If the balloon ascends with a velocity of $$5\ ms^{-1}$$ and descends with a velocity of $$5\ ms^{-1}$$, times taken by the stone to reach the ground in the two cases respectively are ($$g=10\ ms^{-2}$$):

A parachutist after bailing out falls 50 m without friction. When parachute opens, it decelerates at  $$2\ m/ s^{2}$$ . He reaches the ground with a speed of $$ 3\ m/ s$$ .  At what height, did he bail out ? (Given $$g=9.8\ m/s^2$$ approximately)

The average velocity of a body moving with uniform acceleration after travelling a distance of $$3.06\ m$$ is $$0.34\ {m/s}$$. The change in velocity of the body is $$0.18\ {m/s}$$. During this time, its acceleration is