Laws of Motion PHYSICS - Laws of Motion

When you kick a stone, you get hurt. Due to which property this happens?

A woman drawing water from a village well, falls backward, when the rope snaps. This is on account of

Which of the following are vector quantities?

Action-reaction forces

Does a body weigh same at all places of the Earth? Give a reason for your answer.

Define Newton's second law of motion.

State units of momentum in
(1) CGS system
(2) Sl system.

Why is gold not weighed by a spring balance?

Derive the relation between newton and dyne.

State two factors which determine the momentum of a body.

What do you understand by the term momentum?

What do you understand by the following terms?
(a) Contact forces
(b) Non-contact forces

How is weight affected in the following cases, when initially the body is weighed in Delhi with a spring balance?
1. Body is taken to Moscow.
2. Body is taken to Ceylon.
3. Body is taken to sea level.
4. Body is taken to a high mountain.
5. Body is taken deep inside a mine.

A man weighs 800 N the at the equator. How does the weight of man change at the following places?
(a) At poles
(b) 100 km up in space
(c) 10 km down in a mine.

State four differences between mass and weight.

(a) What do you understand by the term weight?
(b) State two important characteristics of weight
(c) State the units of weight in CGS and Sl system.
(d) Name the device used for measuring weight

How is acceleration due to gravity related to
(1) mass of a planet
(2) distance of body from the center of earth?

Explain the following:
1. Why do we jerk wet clothes before spreading them on a line?
2. Why does dust fly off, when carpet is hit with a stick?
3. Why do fruits fall off the branches in the strong wind?
4. Why does a pillion rider fall forward, when the driver of a two-wheeler suddenly applies the brakes?
5. Why does a boatman push the bank backward with a long bamboo pole, on launching his boat in water?
6. Why is it difficult to walk on marshy ground?
7. Why is it dangerous to jump out of a moving vehicle? How can the danger be minimised?
8. Why does a boat-man push water backward with the oars, while rowing a boat?

State Newton's third law of motion and give two examples reaction are equal and opposite.

Prove mathematically F = ma