Notes For Class 9 Science Chapter 1 Law's of motion | Law's of motion notes for class 9 Maharashtra board
Motion :-
The position of an object changes with respect to surrounding called as object are is in motion.
e.g.
1) A flying bird.
2)Throwing a ball..
3)motion of swing.
4) planetary motion.
5) A moving car.
Rest :-
The position of an motion does not change respect to surrounding is called as object with is at rest.
e.g.
1) Door
2) benches in classroom.
3) School, houses
4) mount everest
5) Switch off fan
Distance :-
The actual length travelled by object is called as distance.
e.g.
- SI unit is meter (m)
- It is a scalar quantity
Displacement :-
The minimum distance travelled by an object are called as displacement.
- SI unit is meter (m)
- It is a vector quantity
Notes For Class 9 Science Chapter 1 Law's of motion | Law's of motion notes for class 9 Maharashtra board
# Physical quality
Physical quantity is use for measurement.
Types of physical quantity
- Scalar quantity
- Vector quantity
Scalar quantity :-
A physical quantity has only magnitude.
E.g. distance, speed, time etc.
Vector quantity :-
A Physical quantity have magnitude as well as direction.
E.g. velocity, displacement, force, pressure etc.
Question : the path of length travel by 'A' from 'B' house is 10 km and he is come back again it's original position. Find the distance and displacement.
1. Distance = 10 km + 10 km = 20 km
2. Displacement = zero
Speed :-
The distance traveled by body per unit time is called as speed.
Speed = Distance travelled / Time taken
Question : the distance traveled by a car in 20 seconds is 400 meter find its speed.
Ans.
- SI unit is (m/s).
- CGS unit is (cm/s).
- It is a vector quantity.
Velocity :-
The rate of alter of displacement per unit time is called velocity.
Velocity = displacement / time
- SI unit is (m/s ).
- CGS unit is (cm/s).
- It is a vector quantity.
Notes For Class 9 Science Chapter 1 Law's of motion | Law's of motion notes for class 9 Maharashtra board
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