Forces 1

Question 1

What is a force?

Answer 1

a force is a push or pull on an object caused by it interacting with another object

Question 2

What can (unbalanced) forces do?

Answer 2

when an object experiences a force, it can:

• deform (change shape)
• change speed (move: acceleration, deceleration)

Question 3

Contact or non-contact?

friction

Answer 3

contact

Question 4

Contact or non-contact?

push/pull

Answer 4

contact

Question 5

Contact or non-contact?

drag (water/air resistance)

Answer 5

contact

Question 6

Contact or non-contact?

lift (force on wings that keep it up)

Answer 6

contact

Question 7

Contact or non-contact?

upthrust (upward force exerted on object in liquid)

Answer 7

contact

Question 8

Contact or non-contact?

normal contact force (force exerted on an object through contact with a solid)

Answer 8

contact

Question 9

Contact or non-contact?

weight

Answer 9

non-contact

Question 10

Contact or non-contact?

magnetism

Answer 10

non-contact

Question 11

Contact or non-contact?

electrostatic

Answer 11

non-contact

Question 12

Contact or non-contact?

tension (force in a string holding up a picture)

Answer 12

contact

Question 13

Contact or non-contact?

thrust (propulsive force from an engine)

Answer 13

contact

Question 14

What is weight?

Answer 14

weight is the force acting on an object due to gravity

Question 15

What is weight measured in?

Answer 15

Newtons (N)

Question 16

What is mass measured in?

Answer 16

kilograms (kg)

Question 17

What is gravitational field strength measured in?

Answer 17

Newtons per kilogram (N/kg)

Question 18

What is the formula for weight?

Answer 18

weight = mass x gravitational field strength (W=mg)

Question 19

What is the formula for mass?

Answer 19

mass = weight / gravitational field strength (m=W/g)

Question 20

What is the formula for gravitational field strength?

Answer 20

gravitational field strength = weight / mass (g=W/m)

Question 21

Can mass change?

Answer 21

no

Question 22

Can weight change?

Answer 22

yes

Question 23

What is upthrust?

Answer 23

The upward force exerted on an object that is in or on a fluid

Question 24

What is friction?

Answer 24

The force that opposes movement of an object sliding over a surface

Question 25

What is tension?

Answer 25

The force in a string holding up a picture

Question 26

What is lift?

Answer 26

the force on the wings of an aircraft that keeps it flying

Question 27

What is normal contact force?

Answer 27

the force that a solid surface exerts against an object

Question 28

What is drag?

Answer 28

the force that acts against an object moving through fluid.

Question 29

What is thrust?

Answer 29

the propulsive force from an engine

Question 30

What is electrostatic?

Answer 30

the force between charged particles

Question 31

What is magnetic?

Answer 31

The force between a magnet and an iron nail

Question 32

Elastically deformed

Answer 32

An object has been elastically deformed if it can go back to its original shape and length when the force is removed.

Question 33

Inelastically deformed

Answer 33

An object has been inelastically deformed if it doesn't return to its original shape and length when the force is removed.

Question 34

What is Hooke's law?

Answer 34

The extension of an object that obeys Hooke's law is directly proportionate to the force applied. Any % change in one variable leads to a % change in the other variable.

Question 35

What is the formula for Hooke's law?

Answer 35

Force = spring constant x extension (F=ke)

Question 36

What is force measured in?

Answer 36

Newtons (N)

Question 37

What is the spring constant measured in?

Answer 37

Newtons per metre (N/m)

Question 38

What is the extension measured in?

Answer 38

metres (m)

Question 39

When is Hooke's law applicable?

Answer 39

Hooke's law is only applicable up to the limit of proportionality.

Question 40

What does "∝" mean?

Answer 40

directly proportional

Question 41

What is the "spring constant"?

Answer 41

the spring constant is the measure of the "stiffness" of the spring (how easy it is to stretch)