NCERT Class VIII Science Solutions: Chapter 11-Force and Pressure Part 1

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Question 1:

Give two examples each of situations in which you push or pull to change the state of motion of objects.

Answer:

  • Hitting the ball, coming to us.

  • Kicking to football.

This image shows hitting object their state of motion

Image Shows Hitting Object Their State of Motion

This image shows hitting object their state of motion

Question 2:

Give two examples of situations in which applied force causes a change in the shape of an object.

Answer:

  • Stretching a rubber belt.

  • Reshaping clay to make toys.

Question 3:

Fill in the blanks in the following statements:

  1. To draw water from a well we have to __________ at the rope.

  2. A charged body __________ an uncharged body towards it.

  3. To move a loaded trolley we have to __________ it.

  4. The north pole of a magnet __________ the north pole of another magnet.

Answer:

  1. To draw water from a well we have to pull at the rope.

  2. A charged body attracts an uncharged body towards it.

  3. To move a loaded trolley we have to push it.

  4. The north pole of a magnet repels the north pole of another magnet.

Question 4:

An archer stretches her bow while taking aim at the target. She then releases the arrow, which begins to move towards the target. Based on this information fill up the gaps in the following statements using the following terms:

Muscular, contact, non-contact, gravity, friction, shape, attraction

  1. To stretch the bow, the archer applies a force that causes a change in its _________.

  2. The force applied by the archer to stretch the bow is an example of _________ force.

  3. The type of force responsible for a change in the state of motion of the arrow is an example of a _________ force.

  4. While the arrow moves towards its target, the forces acting on it are due to _________ and that due to _________ of air.

Answer:

  1. To stretch the bow, the archer applies a force that causes a change in its shape.

  2. The force applied by the archer to stretch the bow is an example of contact force.

  3. The type of force responsible for a change in the state of motion of the arrow is an example of a muscular force.

  4. While the arrow moves towards its target, the forces acting on it are due to gravity and that due to friction of air.