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 ?

 

Answer:

  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)