At the top of the trajectory of a projectile, the directions of its velocity and acceleration are
Perpendicular to each other
Parallel to each other
Inclined to each other at an angle of ${45^o}$
Antiparallel to each other
A ball of mass $m$ is thrown vertically upwards. Another ball of mass $2m$ is thrown at an angle $\theta $ with the vertical. Both of them stay in air for same period of time. The heights attained by the two balls are in the ratio of
A small boy is throwing a ball towards a wall $6 \,m$ in front of him. He releases the ball at a height of $1.4 \,m$ from the ground. The ball bounces from the wall at a height of $3 \,m$, rebounds from the ground and reaches the boy's hand exactly at the point of release. Assuming the two bounces (one from the wall and the other from the ground) to be perfectly elastic, .......... $m$ far ahead of the boy did the ball bounce from the ground
If the initial velocity of a projectile be doubled, keeping the angle of projection same, the maximum height reached by it will
Given below are two statements : one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A$ : When a body is projected at an angle $45^{\circ}$, it's range is maximum.
Reason $R$ : For maximum range, the value of $\sin 2 \theta$ should be equal to one.
In the light of the above statements, choose the correct answer from the options given below :
A boy travelling in an open car moving on a levelled road with constant speed tosses a ball vertically up in the air and catches it back. Sketch the motion of the ball as observed by a boy standing on the footpath. Give explanation to support your diagram.