Embibe Experts Solutions for Chapter: Kinematics, Exercise 1: BEGINNER'S BOX - 1

A particle moves on a circular path of radius ’$r$’, It completes one revolution in $40 \mathrm{s}$. Calculate distance and displacement in $2 \min$ $20 \mathrm{s}$.

Three girls skating on a circular ice ground of radius $200 \mathrm{m}$ start from a point $P$ on the edge of the ground and reach a point $Q$ diametrically opposite to $P$ following different paths as shown in figure. What is the magnitude of the displacement for each ? For which girl is this equal to the actual length of path skate?

A wheel of radius ’$R$’ is placed on ground and its contact point is ’$P$’. If wheel starts rolling without slipping and completes half a revolution, find the displacement of point $P$.

A man moves $4 \mathrm{m}$ along east direction, then $3 \mathrm{m}$ along north direction, after that he climbs up a pole to a height $12 \mathrm{m}$. Find the distance covered by him and his displacement.

A person moves on a semicircular track of radius $40 \mathrm{m}$. If he starts at one end of the track and reaches the other end, find the distance covered and magnitude of displacement of the person.

A man has to go $50 \mathrm{m}$ due north, $40 \mathrm{m}$ due east and $20 \mathrm{m}$ due south to reach a cafe from his home.

(a) What distance he has to walk to reach the cafe?

(b) What is his displacement from his home to the cafe?

A ball of mass $1 \mathrm{kg}$ dropped from $9.8 \mathrm{m}$ height, strikes the ground and rebounds to a height of $4.9 \mathrm{m}$. If the time of contact between ball and ground is $0.1 \mathrm{s}$, then find impulse and average force acting on the ball.

A rigid body rotates about a fixed axis with variable angular speed $\omega$ $=A-Bt$ where $A$ and $B$ are constant. Find the angle through which it rotates before it comes to rest.