tell me the important point of
chapter = force and pressure
my paper start in 5 mins
please
Answers
Answer:
Explanation:
Push
A push is a force exerted away from the body, e.g: Hitting a snooker ball, kicking a football
What is a Force?
When a push or pull is applied to an object it is called force.
A force can change the state of an object from rest to motion or vice versa.
To let a force come into play, two or more objects must interact with each other
Characteristics of forces:
When two forces act in the same direction, the net resultant force on an object is the sum of these two forces
When two forces act in opposite directions the net resultant force is the difference of these two forces. The force has a magnitude which describes its strength.
Figure 3 Forces acting in opposite directions
The force always has a direction in which it is applied and a measure of its strength or magnitude.
The effects of a force may alter when the direction of the magnitude of the force is changed.
The effect of more than one forces being applied on an object is calculated by evaluating the net force acting on that object.
If two forces are acting upon each other having equal magnitudes (strength) and in opposite directions then the net force acting on the object will be zero.
Force can bring different effects to an object’s position, size and shape.
Force can change the state of motion of an object
The motion of an object
An object is said to be in motion if it is moving by a certain speed in a particular direction.
If the object is at rest, it means that it is not changing its position with respect to an observing point. Hence it has zero speed.
When the object starts moving it means that its position is being changed with respect to an observation point.
In order to move an object from one place to another, a force is required to bring that object in motion
Pressure
Not only the magnitude of the force but the area upon which it acts also affects the changes it may bring upon an object.
The force acting upon a unit area is called pressure.
Hence, the pressure exerted by an object depends upon its surface area.
If the surface is small, the amount of pressure applied is large, and vice-versa.
The SI unit of Pressure is Pascal (Pa) or N/m2
The pressure exerted by liquids and gases
Liquids exert a pressure on the walls of the container in which they are put in.
The pressure that a liquid exerts on the bottom of the container is dependent upon the height of the liquid in the container.
The liquid exerts equal pressure on different points on the walls of the container having the same depth