Force Theory

Question 1

Define Mass

Answer 1

Amount of matter an object has (measure of an objects inertia. The greater the mass the harder it is the change its motion)

Question 2

Define Weight

Answer 2

Measure of gravity’s pull on an object (It is a force)

Question 3

What will happen to mass and weight when you go to the moon?

Answer 3

It will stay the same because mass is independent from other variables

Question 4

Compare contact and field force and give an example of each

Answer 4

A contact force is when an object applies force through touch (shoving someone or pulling a rope) and a field force is force applies without contact (magnetism)

Question 5

What is inertia

Answer 5

Inertia is “the tendency of an object to resist a change in motion.” (It is NOT a force and it IS a property of matter)

Question 6

If the net force on an object is zero, does that mean the object is not moving?

Answer 6

Although it has a net force of zero it could still be moving at a constant velocity

Question 7

What does net force tell yo about the motion of an object

Answer 7

Gives the magnitude and direction

Question 8

Explain the different between mass and weight

Answer 8

Mass is independent and weight is dependent on mass

Question 9

What is Newtons first law?

Answer 9

An object maintains its state of motion unless it is acted upon by net force

Question 10

What is Newtons second law?

Answer 10

The acceleration of an object is directly proportional to the net force on an object and inversely proportional to the mass of the object

Question 11

What is Newtons third law?

Answer 11

For every action, there is an equal and opposite reaction

Question 12

Friction Force

Answer 12

The contact force that acts to oppose sliding motion between surface and moves parallel to the surface and opposite the direction of sliding

Question 13

Normal Force

Answer 13

The contact force exerted by a surface on an object and moves perpendicular to and away from the surface

Question 14

Spring Force

Answer 14

A restoring force, that is, push or pull a spring exerts on an object and moves opposite the displacement of an object at the end of a spring

Question 15

Tension Force

Answer 15

The pull exerted by a string, rope or cable when attached to a body and pulled taunt and moves away from the object and parallel to the string, rope or cable at the point of attachment

Question 16

Thrust Force

Answer 16

A general term for the forces that move objects such as rockets, planes, cars and people and moves in the same direction as the acceleration of the object barring any resistive forces

Question 17

Weight Force

Answer 17

A long ranged force due to gravitational attraction between two objects, generally Earth and an object and moves straight down toward the center of Earth

Question 18

Applied Force

Answer 18

A physical push or pull. This could be caused by wind pushing on a ship, a child pulling on a wagon, or in the case of our first example, a person pushing a box on the floor.

Question 19

Define Net Force

Answer 19

The total force on the object, taking into account the magnitude and direction of each individual push or pull

Question 20

Equation for mass

Answer 20

m = F
—
g

Question 21

Equation for acceleration

Answer 21

a = Fnet F=ma
———- or
m

Question 22

What is acceleration

Answer 22

The rate of change of velocity

Therefore, if speed or direction changes (either one is considered a change in velocity), the object is accelerating

Question 23

What is a force?

Answer 23

A push or pull upon an object

Question 24

What is the result of interactions between objects?

Answer 24

Object interactions exert forces upon each other. These two forces the object exert on each other and are called action and reaction forces.

Question 25

What pair of forces acting on the two interacting objects?

Answer 25

The size of the forces on the first object equals the size of the force on the second object. The direction of the force on the first object is opposite to the direction of the force on the second object. Forces always come in pairs - equal and opposite, action and reaction

Question 26

Is mass scalar or vector?

Answer 26

Scalar

Question 27

What is weight compared to mass

Answer 27

Weight is directly proportional to mass

Question 28

What does weight depend on?

Answer 28

Magnitude
In fact, an object’s weight is directly proportional to its free fall acceleration (g) at its current location. This is why weight is different on the moon than on Earth.

Question 29

Why are objects difficult to accelerate

Answer 29

We typically think that an object is difficult to accelerate because it is heavy (has weight) - but it is heavy because it has mass.
Because it has mass

Question 30

Newtons first law describes what happened where the is or is not net force?

Answer 30

No net force

Question 31

Newtons second law describes what happened where the is or is not net force?

Answer 31

Yes net force