MEDIUM
JEE Main
IMPORTANT
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If A=2i^+3j^-k^ m and B=i^+2j^+2k^ m. The magnitude of component of vector A along vector B will be _____ m.

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Important Questions on Kinematics

EASY
JEE Main
IMPORTANT
A bullet is shot vertically downwards with an initial velocity of 100 m s-1 from a certain height. Within 10 s, the bullet reaches the ground and instantaneously comes to rest due to the perfectly inelastic collision. The velocity-time curve for total time t=20 s will be : (Take g=10 m s-2)
MEDIUM
JEE Main
IMPORTANT
A ball of mass m is thrown vertically upward. Another ball of mass 2 m is thrown an angle θ with the vertical. Both the balls stay in air for the same period of time. The ratio of the heights attained by the two balls respectively is 1x. The value of x is _____ .
HARD
JEE Main
IMPORTANT
A body of mass 10 kg is projected at an angle of 45° with the horizontal. The trajectory of the body is observed to pass through a point 20,10. If T is the time of flight, then its momentum vector, at time t=T2, is _____ .
[Take g=10 m s-2]
MEDIUM
JEE Main
IMPORTANT
The velocity of the bullet becomes one third after it penetrates 4 cm in a wooden block. Assuming that bullet is facing a constant resistance during its motion in the block. The bullet stops completely after travelling at 4+xcm inside the block. The value of x is
EASY
JEE Main
IMPORTANT
A NCC parade is going at a uniform speed of 9 km h-1 under a mango tree on which a monkey is sitting at a height of 19.6 m. At any particular instant, the monkey drops a mango. A cadet will receive the mango whose distance from the tree at time of drop is :
(Given g=9.8 m s-2)
EASY
JEE Main
IMPORTANT
If the projection of 2i^+4j^-2k^ on i^+2j^+αk^ is zero. Then, the value of α will be
EASY
JEE Main
IMPORTANT
At time t=0 a particle starts travelling from a height 7z^ cm in a plane keeping z coordinate constant. At any instant of time, it's position along the x and y directions are defined as 3t and 5t3 respectively. At t=1 s acceleration of the particle will be
MEDIUM
JEE Main
IMPORTANT
A ball is thrown vertically upwards with a velocity of 19.6 m s-1 from the top of a tower. The ball strikes the ground after 6 s. The height from the ground up to which the ball can rise will be k5 m. The value of k is _____ (use g=9.8 m s-2)