Theme A

Question 1

What is mass the measure of?

Answer 1

Mass is the measure of an objects inertia, its resistance to changing its motion.

Question 2

State the equation for density.

Answer 2

ρ = m / V

Where:
ρ = density
m = mass
V = volume

For a given substance, density is constant.

Question 3

What type of force is weight?

Answer 3

Weight is the gravitational force between an object and the planet it is on; a non-contact force.

Question 4

What base SI units make up a Newton.

Answer 4

Kg⋅m⋅s⁻²

Question 5

State the relation between weight and mass.

Answer 5

F = m⋅g

Where:
F = force, weight
m = mass
g = acceleration due to gravity; 9.8 m⋅s⁻²

Question 6

When is an object in translational equilibrium?

Answer 6

When the vector sum of all forces acting on an object is zero.

Question 7

What is the normal force?

Answer 7

The force in the direction perpendicular to the surface when the object is in contact with a surface.

This force is equal to whatever is necessary for the object to not pass through the surface.

Question 8

What is tension?

Answer 8

The force transmitted through an object when two ends are pulled apart.

Any arbitrary point within the object will feel two equal and opposite tension forces pulling it apart.

Question 9

State the formula for buoyant force?

Answer 9

F = ρ⋅V⋅g

Where:
ρ = density of the fluid
V = volume of submerged portion of the object
g = acceleration of free fall

Question 10

What determines whether an object will float in water or not?

Answer 10

If an object is more dense than the fluid that it is in, it will sink; and float if less dense.

Question 11

State Hooke’s law

Answer 11

F = -k⋅x

Where:

x = length that the spring is deformed
k = spring constant / stiffness

Question 12

Differentiate between elastic and plastic deformations in springs.

Answer 12

Elastic deformations: Deformations that aren’t permanent.
Plastic deformations: Deformations that are permanent.

Question 13

Differentiate between static friction and dynamic friction.

Answer 13

Dynamic friction: The two surfaces are sliding.
Static friction: The two surfaces aren’t sliding.

Question 14

State the equation of dynamic friction.

Answer 14

Ff = μd⋅Fn

Where:

Ff = force of friction
μd = coefficient of dynamic friction
Fn = normal force between the surfaces

Question 15

State the equation of static friction.

Answer 15

Fs ≤ μs⋅Fn

Where:

Fs = force of friction
μs = coefficient of static friction
Fn = normal force between the surfaces

Question 16

What is friction independent of.

Answer 16

The area of the surfaces in contact and the velocity that the surfaces slide.

Question 17

State stoke’s law.

Answer 17

Fd = 6⋅π⋅η⋅r⋅v

Where:

η = viscosity of the fluid
r = radius of the sphere
v = velocity that the sphere falls through the fluid

Question 18

State newtons first law of motion.

Answer 18

An object at rest remains at rest, and an object in motion remains in motion at constant speed and in a straight line unless acted on by an unbalanced force.

Thus an object in translational equilibrium will undergo no acceleration.

Question 19

State newtons second law of motion.

Answer 19

F = m⋅a

Where:

F = force
m = mass
a = acceleration

Question 20

State newtons third law.

Answer 20

Whenever one object exerts a force on a second object, the second object exerts an equal and opposite force on the first.

Question 21

State the formula for work.

Answer 21

W = F⋅s⋅cosθ

Where:

W = work done
F = force
s = displacment
θ = angle between force and displacement

Question 22

State the unit of work and what it is in base SI units

Answer 22

Joule

Newton meter

Kg⋅m²⋅s⁻²

Question 23

In what graph is work the area of

Answer 23

Force displacement graph

Question 24

State the work-energy theorem

Answer 24

W = ∆E

Where:

W = work
∆E = change in energy

Question 25

State v² = u² + 2⋅a⋅s in terms of w

Answer 25

w = (1/2)⋅m⋅v² - (1/2)⋅m⋅u²

Question 26

State the equation for kinetic energy

Answer 26

Eₖ = (1/2)⋅m⋅v²

Where:

Eₖ = Kinetic energy
m = mass
v = velocity

Question 27

State the equation of gravitational potential energy

Answer 27

∆Eₚ = m⋅g⋅∆h

Where:

∆Eₚ = Change in GPE
m = mass
g = acceleration of free fall (-9.8)
∆h = change in height

Question 28

State the equation for elastic potential energy

Answer 28

∆Eₕ = (1/2)⋅k⋅∆x²

Where:

∆Eₕ = elastic potential energy
k = spring constant
∆x = change in spring length

Question 29

State the equation for power

Answer 29

P = ∆W/∆t

Where:

P = power
∆W = work done
∆t = time in seconds

Question 30

State the name of the unit for power and its base SI units

Answer 30

Watt (W)

J⋅s⁻¹

Kg⋅m²⋅s⁻³

Question 31

State the equation for power in relation to force

Answer 31

P = F⋅v

Where:

P = power
F = force
v = velocity

Question 32

State the equation for momentum

Answer 32

P = m⋅v

Where:

P = momentum
m = mass
v = velocity

Question 33

State newtons second law for objects of constant mass.

Answer 33

F = ∆p/∆t

Where:

F = force
∆p = change in momentum
∆t = change in time

Question 34

State the unit of momentum and impulse

Answer 34

Kg⋅m⋅s⁻¹ or newton seconds

Question 35

State the formula for impulse

Answer 35

J = F⋅∆t

Where:

J = momentum
F = force
∆t = duration

Question 36

In what graph is impulse the area of

Answer 36

Force-time graph

Question 37

State the impulse momentum theorem

Answer 37

J = ∆p

Where:

J = impulse
∆p = change in momentum

Question 38

State the equation relating kinetic energy to momentum

Answer 38

Eₖ = p²/(2⋅m)

Where:

Eₖ = kinetic energy
p = momentum
m = mass

Question 39

List the 3 types of collisions

Answer 39

Elastic collision - Kinetic energy is conserved
Inelastic collision - Kinetic energy is lost
Explosions - Kinetic energy is gained

Question 40

What two components can projectile motion be resolved into?

Answer 40

• Uniform horizontal motion with a displacement x, resulting in from an initial velocity uₓ = u⋅cosθ and acceleration aₓ = 0.
• Uniformly accelerated vertical motion with a displacement y, resulting from an initial velocity uᵧ = u⋅sinθ and acceleration aᵧ = -g.