Question 1 Define Newton’s First law of motion?
Question 2 Give example of Newton’s First law of motion?
Question 3 Define the term inertia?
Question 4 What happens to the passengers travelling in a bus when the bus takes a sharp turn?Explain?
Question 5 Explain why it is dangerous to jump out of a moving bus?
Question 6 When a tree is shaken,its fruits and leaves fall down.Why?
Question 7 Which has more inertia,a cricket ball or a rubber ball of same size?
Question 8 When a hanging carpet is beaten with a stick,the dust particles start coming out of it.why?
Question 9 Why do the passengers in a bus falls forward when it starts suddenly?
Newton’s Law of Motion
Newton’s First law of motion
A Body at rest will remain at rest,and a body in motion will continue in motion in a straight line,unless it is compelled by an external force to change its state or of uniform motion.
For Ex:Suppose a book is lying on table(rest).The book will not move by itself,it can change its position only when compelled by force of our hands ie. when we lift the book from the table.Thus,the position of bool has been changed by external force of our hand.
The tendency of a body to remain at rest or if moving continously in a straight line is called inertia.
Inertia is that property of a body due to which it resist a change in its state of rest or of uniform motion.
Greater the inertia of a body,greater will be the force required to bring a change in its state of rest or uniform motion.
If a body has more mass,it has more inertia.
For Ex:Stone has more inertia than football,cricket ball(more mass) has more inertia than rubber ball,body with mass 20 kg will have more inertia than the one with mass 1 kg.
To overcome the inertia and make a body move from rest,we must apply external force.
Newtons’s first law is called Galileo’s Law of Inertia.
1)When a hanging carpet is beaten with stick,the dust particles start coming out of it.Because force of stick,makes carpet to move to and fro but dust particles remain at rest due to inertia and hence separates out.
2)When a tree is shaken vigorously,its fruits and leaves fall down because tree move to and fro but its leaves and fruit remain at rest due to their inertia and hence detach from the tree and fall down.
3)When a car or bus starts suddenly passengers fall backward.This is because of inertia,the passengers tend to remain in their state of rest even when car or bus started moving.
When a running car or bus stops suddenly,the passengers are jerked forward.
When a car or bus turns a corner sharply,we tend to fall sideways.
It is dangerous to jump out of moving bus because the jumping man,who is moving with high speed of bus,would tend to remain in motion even on falling to ground and get hurt due to resistance offered by ground.