Forces (unit 1)

Question 1

What can forces do?

Answer 1

Forces can hold the particles of matter together
they can accelerate and deaccelerate things
they can change the shape of the object
they can change the direction of the object

Question 2

What is the meaning of force?

Answer 2

Force is a push or pull that acts on the object to affects its movement and shape.

Question 3

Is force vector or scaler quantity? and why?

Answer 3

Force is a vector quantity because it has both magnitude and direction

Question 4

what are 2 types of forces?

Answer 4

contact force
non-contact force

Question 5

How many non-contact forces are there and what are they?

Answer 5

Gravitational force
Electrostatic force
Magnetic force

Question 6

what is the other name of the force of gravity on an object?

Answer 6

Weight of the object

Question 7

What does gravitational force do?

Answer 7

It attracts the object to the center of the earth.

Question 8

How much is gravitational force?

Answer 8

10N/kg

Question 9

Which kind of object have gravitational force?

Answer 9

Objects which have mass

Question 10

What is electrostatic force?

Answer 10

Force between 2 charges

Question 11

What is magnetic force?

Answer 11

force between 2 poles of magnets or magnets and magnetic materials

Question 12

What is friction?

Answer 12

Friction is the force that act against the motion of the object when 2 surface rubbed against each other.

Question 13

Name one thing that friction depend on?

Answer 13

smoothness or roughness of the surface

Question 14

Does mass of the object depend on friction? explain with example.

Answer 14

yes, if we take a box of lead and a box of paper which have same volume, despite giving the same force, the box with paper can move faster than the box of lead.

Question 15

When do we need less friction and when do we need big friction?

Answer 15

we need less friction if we want to move around freely, and we have more friction if we want to deaccelerate or stop things.

Question 16

What is reaction force?

Answer 16

force that act against the action force

Question 17

Why friction act opposite to motion of the body?

Answer 17

Because it is a resistive force

Question 18

What is air resistance?

Answer 18

air resistance is the force that act on the objects in the air to affect its movement when the air particles collide with the objects.

Question 19

What is water resistance?

Answer 19

water resistance is the force that act on the objects in the water to affect its movement when the water particles collide with the objects.

Question 20

Are water and air resistance type of friction?

Answer 20

Yes

Question 21

What is drag force?

Answer 21

Force that act against the motion of objects in the air or water.

Question 22

What air and water resistance are called drag force?

Answer 22

Because they slow down the motion of the objects

Question 23

Every action has ——– force.

Answer 23

Reaction

Question 24

What is upthrust force?

Answer 24

Upthrust force is the upward force that acts on the objects floating in the air or in the water which push the objects upward.

Question 25

Which force is opposite of upthrust?

Answer 25

Gravity

Question 26

What is upthrust force of water called?

Answer 26

Buoyancy

Question 27

What 2 forces are that against the motion of the objects?

Answer 27

Friction and drag force

Question 28

What is Thrust?

Answer 28

engine force which acts against the drag force

Question 29

Which force is the opposite direction of Thrust?

Answer 29

Drag force

Question 30

What happened when thrust and drag forces are balanced?

Answer 30

There will be no change in motion.

Question 31

What happened when trust is more than drag and less than drag?

Answer 31

In jet, if the thrust is more than drag the jet will accelerate and if the drag is more than thrust the jet will deaccelerate.

Question 32

What can you know if the object has constant velocity?

Answer 32

Forces acting on the objects are balanced.

Question 33

What happened when the 2 opposite forces are balanced and when they are unbalanced?

Answer 33

If the 2 opposite force in object is balanced there will be no change in motion if not, the object will move forward or accelerate to the bigger force direction.

Question 34

What is Tension?

Answer 34

Stretching force when we pull objects with ropes.

Question 35

Which objects change shape temporarily?

Answer 35

Elastic objects

Question 36

How elastic objects change shape?

Answer 36

When the force is applied to them, they change shape temporarily and as long as they don't stretch beyond their elastic limit, once the force is removed, they will return to their original shape.

Question 37

Is coil style in spring helpful in withstanding weight?

Answer 37

Yes

Question 38

What is force relation to extension?

Answer 38

Directly proportional

Question 39

What is Hooke's law?

Answer 39

Hooke's law is where the extension of the spring is proportional to the force.

Question 40

In plotted graph when do we know when the spring doesn't obey hook laws anymore?

Answer 40

The starting point of curve line is the point where the elastic object doesn't obey Hooke's law

Question 41

What happened if the elastic objects stretched beyond limit of proportionality?

Answer 41

It will no longer obey Hooke's law.

Question 42

What happened if the elastic object stretched beyond elastic limit?

Answer 42

It will no longer returned to its original shape.

Question 43

For many metals, elastic limit is the same as limit of proportionality?

Answer 43

True

Question 44

Hooks law formula?

Answer 44

F(force) = constant) x(extension)

Question 45

What is centripetal force?

Answer 45

force that makes the objects to move in circular way.

Question 46

What is centripetal force direction?

Answer 46

Always toward the center of the circle

Question 47

Object velocity which has centripetal force ...........

Answer 47

is always perpendicular to the centripetal force.

Question 48

Without centripetal force, the object can't travel in ......

Answer 48

Circular way

Question 49

What is resultant force?

Answer 49

Force that is equivalent to 2 or more forces acting on the object.

Question 50

Which signs show that the force is acting on opposite direction?

Answer 50

+ and -