H C Verma Solutions for Chapter: Rest and Motion : Kinematics, Exercise 1: QUESTIONS FOR SHORT ANSWER

Galileo was punished by the church for teaching that the sun is stationary and the earth revolves around it. His opponents held the view that the earth is stationary and the sun revolves around it. If the absolute motion has no meaning, are the two viewpoints not equally correct or equally wrong?

A car travels at a speed of $60 \mathrm{km} {\mathrm{h}}^{-1}$ due north and the other at a speed of $60 \mathrm{km} {\mathrm{h}}^{-1}$ due east. Are the velocities equal? If no, which one is greater? If you find any of these questions irrelevant, explain.

At which point on its path a projectile has the smallest speed?

Give example where (a) the velocity of a particle is zero but its acceleration is not zero (b) the velocity is opposite in direction to the acceleration, (c) the velocity is perpendicular to the acceleration.

The figure shows the $x$-coordinate of a particle as a function of time. Find the signs of $v_{\mathrm{x}}$ and $a_{\mathrm{x} }$at  $t=t_1$, $t=t_2$ and $t=t_3$

A player hits a baseball at some angle. The ball goes high up in space. The same player runs and catches the ball before it hits the ground. Which of the two (the player or the ball) has greater displacement?

The increase in the speed of a car is proportional to the additional petrol put into the engine. Is it possible to accelerate a car without putting more petrol or less petrol into the engine?

Rain is falling vertically downwards. A man running on the road keeps his umbrella tilted but a man standing on the street keeps his umbrella vertical to protect himself from the rain. But both of them keep their umbrella vertical to avoid the vertical sun-rays. Explain.