Forces

Question 1

What are the three properties of a force

Answer 1

Magnitude
Point of application
Direction

Question 2

What are the two components of direction

Answer 2

Line of action
Sense

Question 3

What do you need to fully describe a force?

Answer 3

Its size and direction

Question 4

Define direction

Answer 4

the way the force is applied
(arrow head)

Question 5

Define magnitude

Answer 5

The size of the applied force (length)

Question 6

Define point of application

Answer 6

The point at which the system receives the applied force

Question 7

Define line of action

Answer 7

The imaginary line extending indefinitely along the vector through the tip and tail (shaft)

Question 8

What is a contact force

Answer 8

The result of physical contact between two bodies

Question 9

What can be classified as contact or non-contact forces

Answer 9

External forces

Question 10

T/F Force is directly proportional to mass

Answer 10

True

Question 11

What type of force is someone pushing on a desk

Answer 11

Action force

Question 12

What type of force is a desk “pushing back” on someone pushing it

Answer 12

A reaction force

Question 13

What is newtons third law?

Answer 13

Forces come in pairs, with every action there is an equal and opposite reaction

Question 14

Describe the forces when someone jumps in the air

Answer 14

The person pushing on the ground is the action force. The ground pushing the person up into the air is the reaction force.

Question 15

Describe external forces

Answer 15

They interact with the system from the outside

Only external forces can change the motion of a system

Question 16

Describe internal forces

Answer 16

They act within the defined system
Only internal forces can change the shape of the system

Question 17

Is the floor an internal or external force when someone is walking

Answer 17

External

Question 18

Define a motive force

Answer 18

A force that tends to lead to a change in motion in the form of increased velocity or change in direction of the system

Question 19

Define a resistive force

Answer 19

A resistive force tends to prevent changes in motion by other external forces or decrease the velocity of a system that is already in motion

Question 20

Describe the forces when someone is skydiving

Answer 20

Gravity is the motive force and air resistance is the resistive force

Question 21

T/F if a force tends to lead to a change of motion in the form of increased velocity of the system, then the force is resitive

Answer 21

False, the force is motive

Question 22

Where is gravitational pull concentrated

Answer 22

At the center of mass

Question 23

What type of force is gravity

Answer 23

Non-contact
Active
External

Question 24

Define static friction

Answer 24

It is when two contacting surfaces are not currently sliding relative to each other but do possess the potential for movement

Question 25

Define kinetic friction

Answer 25

It is when the two contacting surfaces are already sliding relative to each other

Question 26

Define rolling friction

Answer 26

When one surface is rolling over another but not sliding

Question 27

Which type of friction coefficient is the strongest in decreasing order

Answer 27

Static > dynamic (kinetic) > rolling

Question 28

What is limiting friction

Answer 28

The maximum friction that you can get from the ground to counter external force

Question 29

Give an example of motive friction

Answer 29

The friction of your foot and the ground when you walk

Question 30

What does the complexity of vector composition depend on

Answer 30

The number of vectors and the relative directions and orientations of the vectors

Question 31

What is vector resolution

Answer 31

The process used to resolve a single vector into its individual directional component vectors