Force and Pressure

Answer the following:

Q1) What is the relationship between force and speed

Ans:

Applying force on a moving object can either stop it or make it move faster.

Q2) When do the forces acting on an object add up ?

Ans:

When two forces are applied on an object in the same direction they are added up.

Q3) Name two noncontact forces?

Ans:

Magnetic force, electrostatic force are noncontact forces.

Q4) what is contact force?

Ans:

When force acting on an object is in contact with the object, the force is known as contact force.

Push and pull are contact forces.

Q5) what is magnetic force?

Ans:

The force iron exerted by a magnet on certain metals is known as magnetic force.

The pull with which the magnet attracts the iron objects is due to the magnetic force.

Q6) Define gravitational force?

Ans:

The invisible force exerted by the earth on all kinds of matter is called force of gravity.

Q7) Define pressure

Ans:

Pressure is the result of force exerted over an area.

The amount of force that presses on a certain area is known as pressure.

Q8) What is the unit of pressure?

Ans:

The SI unit for measuring pressure is Pascal (Pa)

 

Q9) what is atmospheric pressure ?

Ans:

Atmospheric pressure is defined as the force per unit area exerted on a surface by the weight of the air above it.   

Q10) Give an example to illustrate that force can change the speed of a moving object.

Ans:

The distance traveled by a moving object on any given surface        depends on the amount of force applied to it. If the force applied is less , it travel slowly and covers a shorter distance. If  the force applied is greater, it travel farther and faster.

Q11) what is the net force when two equal and opposite forces act on an object.

Ans:

If equal and opposite forces act on an object, the object remains stationary and does not move in either direction. The net force on the object is the difference between the two forces ( zero ) .

Thus the net force acts in the direction of the larger force.

Q12) what is the net force when two forces are applied on an object in the same direction ?

Ans:

When two forces are applied on an object in the same direction, they add up and the sum of the forces acts on the object.

Thus, the net force is the total of the two forces acting in the same direction.

Q13) what is electrostatic force ?

Ans:

When a plastic ruler is rubbed against dry hair, it acquires electrostatic charge due to which the ruler is able to pull a strip paper.

This force is known as electrostatic force.

Q15) why is gravity a noncontact force?

Ans:

Gravity is a noncontact force.

The earth does not have to be in contact with the object on which it exerts force.

The force of gravity acts on an object is irrespective of whether the object is in the air, water or on the ground.

Q16) explain weight.

Ans:

The gravitational force experienced by an object is its weight and measured using a spring balance .

Q17) Why does pressure increase with the depth of a water column.

Ans:

Pressure exerted by a liquid increases with depth in an ocean or a lake.

The pressure increases with the depth of the water. in deep water, there is more water piled up , which causes the pressure to be very high at the bottom .

Q18) how does a pin pierce a board?

Ans:

when a pin is pushed, the force applied on the end of the pin.

This force get transferred to the narrow pointed end .the force you apply on a large area acts on the point of the pin.

As a result The point  experience grater amount of pressure and  it extent amount .