Chap-8

Question 1

What is force?

Answer 1

Force is a pull or a push upon an object

Question 2

a)Force is a vector quantity that has____ and ___. b)Force also has ___

Answer 2

a) magnitude ; direction
b )point

Question 3

S.I. unit for force is ?

Answer 3

Newton,(N)

Question 4

Newton’s Third Law states what ?

Answer 4

Newton’s Third Law states that for every action force, there is a reaction force of the same magnitude but in the opposite direction

Question 5

Effects of force ?

Answer 5

-Force can change shape, size and motion of the object
1.Moving a stationary object
2.Stopping a moving object
3.Changing the speed of an object that is in motion
4.Changing the direction of an object that is in motion
5.Changing the shape and size of an object

Question 6

Explain Buoyant Force and Density .

Answer 6

Buoyant force = Actual weight - Apparent weight

1.The denser the object, the lesser the buoyant force than the object. Thus, the object submerge
2.The less dense the object, the higher the buoyant force than the object. Thus, the object float

Question 7

What is Effort in Lever?

Answer 7

Force applied on the bar

Question 8

What is Load in Lever?

Answer 8

Object to be moved

Question 9

What is Fulcrum in Lever?

Answer 9

Fixed support point

Question 10

How many Classification of levers are there ? Explain them .

Answer 10

FLE
123

Question 11

What is the formula for The Moment of Force ?

Answer 11

Moment of force = Force(N) x Perpendicular distance from the pivot to the (m)

Question 12

Define pressure .

Answer 12

Pressure is defined as force per unit area (direction of force is perpendicular to the surface area)

Question 13

What is S.I unit for pressure ?

Answer 13

pascal (Pa)

Question 14

What is the formula to calculate pressure ?

Answer 14

Pressure = Force (N) / Surface area (m2)

Question 15

The frequency of collision between the air molecules and the walls of the container will produce a force that pushes against the walls which is called ?

Answer 15

air pressure / gas pressure

Question 16

How does volume affect gas pressure ?

Answer 16

Decreasing the volume of a contained gas will increase its pressure, and increasing its volume will decrease its pressure.

Question 17

How does temperature affect gas pressure ?

Answer 17

When the temperature of the container increases, the kinetic energy of the gas molecule becomes high. This means the collision rate of the particles increases. Due to the collision of gas particles, the pressure increases across the wall of the container.

Question 18

What is Atmospheric Pressure ?

Answer 18

Atmospheric pressure is the pressure exerted by the atmosphere on the surface of the Earth and all objects on the Earth.

Question 19

Explain the atmospheric pressure applied to a plunger .

Answer 19

If you press on the plunger, you increase the pressure of the air and thus the air in the balloon contracts or decreases its volume.

Question 20

Explain the atmospheric pressure applied to a straw .

Answer 20

Since the atmospheric pressure is greater on the outside of the straw, liquid is forced into and up the straw and into your mouth

Question 21

What is the Relationship between Altitude and Atmospheric Pressure ?

Answer 21

Atmospheric pressure decreases as altitude increases

Question 22

Effects of Depth on Liquid Pressure applied to a dam ?

Answer 22

The walls of a dam are designed to be thicker at the base in order to withstand the high water pressure at the base of the dam.

Question 23

Why do divers wear a special suit while diving ? why can’t they wear a normal t-shirt while diving?

Answer 23

A diver wears a special suit in order to withstand high water pressure. Whereas , normal clothing won’t be able to withstand the high water pressure.