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Is the child pushing or pulling to stretch the bow? How will the effect be different in
each of the pictures and why?
Answers
Answer:
1. Give two examples each of situations in which you push or pull to change the state of motion of objects.
ans. We push a bicycle to move it, we pull the table to change its position.
2. Give two examples of situations in which applied force causes a change in the shape of an object.
ans. when we press the foam, its shape is changed.
when we stretch the rubber band, its shape is changed.
3. Fill in the blanks in the following statements.
(a) To draw water from a well we have to ______ at the rope.
(b) A charged body______ an uncharged body towards it.
(c) To move a loaded trolley we have to ________ it.
(d) The north pole of a magnet _____ the north pole of another magnet.
ans. (a) To draw water from a well we have to pull at the rope.
(b) A charged body attracts an uncharged body towards it.
(c) To move a loaded trolley we have to pull it.
(d) The north pole of a magnet repels the north pole of another magnet.
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 statements using the following terms. Muscular, contact, non-contact, gravity, friction, shape, attraction
(a) To stretch the bow, the archer applies a force that causes a change in its ______.
(b) The force applied by the archer to stretch the bow is an example of ________ force.
(c) The type of force responsible for a change in the state of motion of the arrow is an example of a ______ force.
(d) While the arrow moves towards its target, the forces acting on it are due to ____ and that due to __________ of air.
ans. 4. (a) shape (b) muscular (c) contact (d) gravity, friction.
5. In the following statements identify the agent exerting the force and object on which its acts. State the effect of the force in each case.
(a) Squeezing a piece of lemon between the fingers to extract its juice.
(b) Taking out paste from a toothpaste tube.
(c) A load suspended from a spring while its other end is on a hook fixed to a wall.
(d) An athlete making a high jump to clear the bar at a certain height.
ans. Agents exerting forceObject on which force actsEffect of force (a) Fingers LemonLemon juice is extracted (b) Fingers Toothpaste tubeToothpastes comes out (c) A load Spring The spring expands (d) An athlete On the legs Cleans the height