Forces and Laws of Motion-Important Questions

1.  State two effects of force.

2.  Scientist who first conducted experiment to form the base for Newton's first law of motion.

3.  If first law of motion holds true, why does a ball rolling on ground stop on its own?

4.  What would happen if there was no friction on the Earth?

5.  What would happen if gravitational force of the Sun suddenly vanishes?

6.  What did Galileo observe by placing two inclined planes facing each other and rolling down a marble ball from top end of one of them?

7.  What is the negative effect of friction on your shoe soles?

8.  You are applying force on the pan of single pan weighing balance and the pointer points to 100 g. What is the force in newtons applied by you?

9.  An athlete always runs some distance before taking a jump. Why?

10.  A cricket ball of mass 70 g moving with a velocity of 0.5 m/s is stopped by a player in 0.5 s. What is the force applied by the player to stop the ball?

11.  In a cricket match, why does a player lower his hands slightly while catching the ball?

12.  Two cars having masses in the ratio 4 : 5, accelerate in the ratio 2:3. Find the ratio o forces exerted by each of them.