# Force and laws of motion Worksheet-7

Force and laws of motion Worksheet-7

1. State the relation between the momentum of a body and the force acting on it.

1. What is the unit of force ?

1. Define one newton force.

1. What is the relationship between force and acceleration ?

1. If the mass of a body and the force acting on it are both doubled, what happens to the acceleration ?

1. Name the physical quantity whose unit is 'newton'.

1. Which physical principle is involved in the working of a jet aeroplane ?

1. Name the principle on which a rocket works.

1. Is the following statement true or false :

A rocket can propel itself in a vacuum.

1. What is the force which produces an acceleration of 1 m/s2 in a body of mass 1 kg ?

1. Find the acceleration produced by a force of 5 N acting on a mass of 10 kg.

1. A girl weighing 25 kg stands on the floor. She exerts a downward force of 250 N on the floor. What force does the floor exert on her?

1. Name the physical quantity which makes it easier to accelerate a small car than a large car.

1. Explain the meaning of the following equation :

F = m × a

Where symbols have their usual meanings.

1. To take the boat away from the bank of a river, the boatman pushes the bank with an oar. Why?

1. Why does a gunman get a jerk on firing a bullet?

1. If action is always equal to reaction, explain why a cart pulled by a horse can be moved.

1. Explain how a rocket works.

1. Do action and reaction act on the same body or different bodies ? How are they related in magnitude and direction? Are they simultaneous or not ?

1. If a man jumps out from a boat, the boat moves backwards. Why ?

1. where F is force and m is momentum.

1. newton

1. A Newton is that force which when acting on a body of mass 1 kg produces an acceleration of 1 m/s2 in it.

1. Force = mass × acceleration.

1. Acceleration remains the same

1. force

1. Principle of conservation of momentum

1. True

1. 1 newton (1 N)

1. 0.5 m/s2

Using Force = mass × acceleration.

1. 250 N

1. Mass (of the car)