Force and Laws of Motion

CSCE TUTORIAL

Force and Laws of Motion

Worksheet-1

 

1. Which of the following has more inertia:

         (a)  a rubber ball and a stone of the same size?

         (b)  a bicycle and a train?

         (c)  a five rupees coin and a one-rupee coin?

2. Explain why some of the leaves may get detached from a tree if we vigorously shake its branch.

3. Why do you fall in the forward direction when a moving bus brakes to a stop and fall backwards when it accelerates from rest?

4. A constant force acts on an object of mass 5 kg for a duration of 2 s. It increases the object’s velocity from 3 m s–1 to 7 m s-1. Find the magnitude of the applied force. Now, if the force was applied for a duration of 5 s, what would be the final velocity of the object?

5. A motorcar is moving with a velocity of 108 km/h and it takes 4 s to stop after the brakes are applied. Calculate the force exerted by the brakes on the motorcar if its mass along with the passengers is 1000 kg.

6. A force of 5 N gives a mass m1 , an acceleration of 10 m s^–2 and a mass m² , an acceleration of 20 m s^-2 . What acceleration would it give if both the masses were tied together?

7. Explain why it is difficult for a fireman to hold a hose, which ejects large amounts of water at a high velocity.

8. When a carpet is beaten with a stick, dust comes out of it. Explain.

9. A stone of 1 kg is thrown with a velocity of 20 m s^–1 across the frozen surface of a lake and comes to rest after travelling a distance of 50 m. What is the force of friction between the stone and the ice?

10. An object of mass 100 kg is accelerated uniformly from a velocity of 5 m s^–1 to 8 m s^–1 in 6 s. Calculate the initial and final momentum of the object. Also, find the magnitude of the force exerted on the object.

11. How much momentum will a dumb-bell of mass 10 kg transfer to the floor if it falls from a height of 80 cm? Take its downward acceleration to be 10 m s^–2 .