Question

E. Short answer type questions :
1. What is friction?
2. Explain the role of area of contact on pressure with an example.
3. What is gravity?
4. Explain the net effect of force when two bodies apply force on an object.
5. How can you say liquid exerts pressure on the walls of container?
E. Long answer type questions:
1. Explain the effects of force.
2. Write a short note on atmospheric pressure.
3. Write some applications of pressure?​

Answer 1

Answer:

Do by your own. It will increase your knowledge.

Answer 2

Answer:

1. Friction is the resistance to motion of one object moving relative to another. It is not a fundamental force, like gravity or electromagnetism. Instead, scientists believe it is the result of the electromagnetic attraction between charged particles in two touching surfaces.
2. When we walk in high heels the area of the contact of the heels with the surface is very small and hence the pressure exerted will be very high so is the pressure exerted on the body.
3. an invisible force that pulls objects toward each other. Earth's gravity is what keeps you on the ground and what makes things fall. ... Earth's gravity comes from all its mass. All its mass makes a combined gravitational pull on all the mass in your body.
4. When two forces are applied on an object in opposite directions, the net force on the object is the difference between the forces; this net force acts in the direction of the greater force.
5. All the liquids exert pressure on the base or bottom and walls of their container. All the liquid have weight. When we pour liquid into a vessel, then the weight of liquid pushes down on the base of the vessel producing a pressure. The liquid exerts pressure on the base of the vessel

1.Effects of Force

A force acting on an object causes the object to change its shape or size, to start moving, to stop moving, to accelerate or decelerate. When there’s the interaction between two objects they exert a force on each other, these exerted forces are equal in size but opposite in direction. When an object has several forces acting on it, the effects of force is same as one force acting on the object in a certain direction and this overall force is called the ‘resultant force’. The resultant force is essential to change the velocity of an object.

• If the resultant force is zero the forces on the object are balanced.

• If the resultant force acting on the object is ‘zero’ then: the object will remain stationary. In such a case the object will move at a steady speed in a straight line.

• If the resultant force acting on the object isn’t zero then: the object will either accelerate or decelerate.

2.Atmospheric pressure is a force in an area pushed against a surface by the weight of the atmosphere of Earth, a layer of air. ... This is because high places do not have as much air above them, pushing down. Barometers can be used to measure atmospheric pressure. There is the same atmospheric pressure from all directions.

3.Applications of Pressure in Daily Life

1. The area of the edge of a knife's blade is extremely small. ...
2. Syringes are used to take blood for blood tests. ...
3. When air is sucked out of a drinking straw, the air pressure inside if decreases and the atmospheric pressure outside forces the liquid to go inside the straw.