Forces and Interaction

Question 1

What is weight?

Answer 1

Force of gravity on an object.
Weight = Mass * Gravity
Measured in Newtons

Question 2

What is gravity?

Answer 2

It is the force that attracts objects within the atmosphere toward the center of the Earth. It is the force of attraction between two objects. Acceleration due to gravity on Earth is 9.8 Newtons.

Question 3

What is mass?

Answer 3

Anything that occupies space and has matter. It is the amount of matter in an object. Mass’s SI unit is Kg

Question 4

Difference between mass and weight.

Answer 4

Mass
1. Anything that occupies space and has matter
2. SI unit = Kg
3. Remains constant
4. Doesn’t depend on weight

Weight
1. Force of gravity on an object
2. SI unit = Newtons
3. Varies from place to place
4. Depends on mass

Question 5

What is force?

Answer 5

A push/pull acting on an object. SI unit - Newtons

Question 6

What are newtons?

Answer 6

SI unit of force and weight. 1 Newton is the amount of force that causes a mass of 1 kg to accelerate at m/s^2

Question 7

What is Net Force?

Answer 7

It is the overall force acting on a object that takes into account all of the individual forces acting on an object. It is a single force that replaces the effect of the original forces on the particles motion.

Question 8

What are balanced forces?

Answer 8

When two equivalent forces act upon each other. Ex: Book on table

Question 9

What are unbalanced forces?

Answer 9

Two unequal forces are acting upon each other. Ex: Tug of war

Question 10

What are the types of forces?

Answer 10

Contact Forces
1. Applied force
2. Normal force
3. Frictional force
4. Tension force
5. Spring force

Non-Contact forces
1. Gravitational
2. Magnetic
3. Electrostatic

Question 11

What is normal reaction force?

Answer 11

The force that is exerted upon an object that is in contact with another stable object. Ex book on a table
It is exerted perpendicularly between two objects that are in contact with each other.

Question 12

What is Frictional force?

Answer 12

Force exerted by a surface as an object moves across it, or makes an effort to. Also known as opposing force.
There are two types of frictional forces:
1. Static friction - Force keeps objects at rest.
2. Sliding friction - Force exerted by any two objects when sliding against each other.

Question 13

What is tension force?

Answer 13

It is a force that is transmitted to a string, rope, cable, or wire when pulled tightly from forces acting in opposite directions

Question 14

What is spring force?

Answer 14

The force is exerted by a spring when it is stretched or compressed.
The force created by the spring is proportional to the amount of spring stretched or compressed.

Question 15

What are the causes of friction?

Answer 15

1. Due to rough surface
2. Due to the machinery of machine’s
3. Due to irregularities of two surfaces in contact.

Question 16

How can we reduce the force of friction?

Answer 16

1. By adding lubricants
2. By using ball bearings
3. By smoothening the surface
4. By streamlining the body.

Question 17

State newtons first law of motion

Answer 17

Newton’s first law of motion states the motion of an object won’t change unless there is an unbalanced force acting upon it. Every object continues to be in the state of rest or uniform motion unless and until an external force is applied to it.
Inertia or rest - Tendency of an object to continue in the state of rest.
The inertia of motion - Tendency of an object to continue in the state of motion
The inertia of direction - The tendency of an object to continue in the same direction while in motion

Question 18

What does Newtons second law state

Answer 18

Newton’s second law states that the acceleration of an object equals the net force acting on the object divided by the mass of the object.
The rate of change in momentum is directly proportional to the force applied to it.
Acceleration = Net force/mass, A = f/m
A is directly proportional to f and inversely proportional to m

F = ma (a=9.8m/s)

Question 19

What does Newtons third law state?

Answer 19

Newton’s third law states that every action has an equal and opposite reaction. This means that forces always act in pairs.

Question 20

What is momentum?

Answer 20

It is the property of a moving object that makes it hard to stop. It is the product of mass velocity.

Question 21

What does the law of conservation of momentum state?

Answer 21

The law of conservation of momentum states that when an action and reaction occur, momentum is transferred from one object to another but their combined momentum remains the same.

Question 22

How does an objects mass affects its inertia?

Answer 22

Objects with greater mass have greater inertia.