Embibe Experts Solutions for Chapter: Kinematics, Exercise 3: Level 3

A train of length $210 \mathrm{m}$ is moving with a speed of $25 \mathrm{m} {\mathrm{s}}^{-1}$ in North direction. A small bird is flying above the train with a speed of $5 \mathrm{m} {\mathrm{s}}^{-1}$ in south direction. Find the time taken by the bird to cross the train in seconds.

A boy standing on the foothpath tosses a ball straight up and catches it. The driver of a car passing by moving with uniform velocity sees this.

The trajectory of the ball as seen by the driver will be

A ball of mass $m$ is thrown upward with a velocity $v$. The air exerts an average resisting force $F$. The velocity with which the ball returns to the thrower is

The velocity displacement graph of a particle moving along a straight line is shown.

The most suitable acceleration-displacement graph will be

A mobile phone of mass $100 \mathrm{g}$ falls from the hand of a person through the window of a train. The train is accelerating at $1 \mathrm{m} {\mathrm{s}}^{-2}$ and just $20 \mathrm{s}$ have passed since it left the station from standstill. If the window is $2 \mathrm{m}$ above the ground. With what kinetic energy will the phone will hit the ground? $\left(g=10 \mathrm{m} {\mathrm{s}}^{-2}\right)$

A particle of mass $10 \mathrm{g}$ moves along a circle of the radius $\frac{1}{\pi } \mathrm{cm}$ with a constant tangential acceleration. What is the magnitude of this acceleration (in $\mathrm{m} {\mathrm{s}}^{-2}$) if the kinetic energy of the particle becomes equal to $8\times {10}^{-4}\mathrm{ }\mathrm{J}$ by the end of the second revolution after the beginning of the motion? (Particle starts from rest)

A bird is tossing (flying to and fro) between two cars moving towards each other on a straight road of which one car has a speed of 18 km/h while the other has the speed of 27 km/h. What is the total distance(in km) covered by the bird when the bird starts moving from first car towards the other and is moving with the speed of 36 km/h and when the two cars were separated by 36 km?