Question & Answers -1 of ch-3 (force) of class-6

 1. Name the term used for the push or pull.

Ans. Force.

2. Give one example each of a force as

 1. a push        

 2.as pull 3.a stretch and 4.a squeeze.

Ans.a) as push- To open a door,we push it.

        b) as pull- we pull a door to open it.

        c)a stretch-on stretching a spring, it elongates.

        d)a squeeze-on squeezing a tubeof gum ortoothpaste, its shape changes.

3. Explain the meaning of the term force.

Ans. A force is that cause which changes the the state of a body either the state of rest or the state of motion or the direction of motion or changes the size or shape of the body.

4. What effect can a force have on a stationary body?

Ans. A force can move a body i.e.,changes from state of rest to state of motion.

5. What effects can a force have on a moving body?

Ans.A force can stop a moving body i.e., changes from state of motion to state of rest.

6. What effect can a force produce on a body which is not allowed to move?

Ans.shape & size of a body can be changed. Eg. If an inflated balloon is pressed ,its shape changes.

7. Give 1 example each  to indicate that the application of a force

a) produces motion- A ball lying on the geound moves, when it is kicked.

b) stops motion- A moving cricket ball is stopped by the fielder when he catches it, by applying force.

c) slows down motion- A swing can be slowed down if a boy instead of pushing it,pulls the swing in the opposite direction.

d) changes the direction of motion- In tennis,the direction of motion of the ball is changed by hitting it in opposite direction.

e) deforms a body- On squeezing a piece of rubber,its shape changes.

8. State the the effect produced by a force in the following cases

a) The sling of a rubber catapult is stretched

    Length of rubber increases.

b)A man pushes a heavy cart - cart starts slidding (changes its state from rest to state of motion).

c)A player uses his stick to deflect the ball-changes the direction of the moving ball.

d)A cyclist applies brakes-bicycle slows down and finally comes to rest.

e)A spring is compressed-length decreases.

9. Name the the two kinds of forces in nature.

Ans. The the two kinds of forces are contact forces and non contact forces.

Contact force-The  force which acts on bodies by making an actual contact , is called the contact force.eg muscular force,tension force etc.

Non-contact force -The forces which act on bodies with no contact with them are called the non-contact forces or the forces from a distance.eg.Gravitational force,Magnetic force etc.

10. Name the type of force which acts in the following cases:

a)A Coolie  lifts a luggage-contact force(Muscular force)

b) A bicycle comes to rest slowly when the cyclist stops pedalling- contact force(force of friction)

c) A stone falls from a roof-Non-contact force(Gravitational force)

d)A comb rubbed with Silk attracts the bits of paper-non-contact force(electrostatic force)

e) A string hangs with a load-contact force(force of tension)

f)A horse moves a cart-contact force(muscular force)

g) A magnet attracts an iron pin-non-contact force(magnetic force)

h)A boy opens the door-contact force(muscular force)

i)An apple falls from a tree- non-contact force(Gravitational force)

j)A man rows a boat-contact force(muscular force)