Topic 2 - Mechanics

Question 1

State the 4 Equations of Motion.

Answer 1

v = u +at
s = (u+v)t / 2
s = ut + 1/2 at^2
v^2 = u^2 + 2as

Question 2

Define Speed.

Answer 2

The Rate of Change of Distance.

Question 3

State the Equation for Calculating Speed.

Answer 3

Speed = Distance/Time

Question 4

Define Velocity.

Answer 4

The Rate of Change of Displacement.

Question 5

State the Eqaution for Calculating Velocity.

Answer 5

v = Change in Distance/Change in Time

Question 6

Define Acceleration.

Answer 6

The Rate of Change of Velocity.

Question 7

State the Equation for Calculating Acceleration.

Answer 7

a = Change in Velocity/ Change in Time.

Question 8

Define Uniform Acceleration.

Answer 8

The Acceleration of an Object is Constant.

Question 9

State what Acceleration-Time Graphs Represent.

Answer 9

Change in Velocity over Time.

Question 10

State what the Area under an Acceleration-Time Graph Represents.

Answer 10

Change in Velocity.

Question 11

On an Acceleration-Time Graph, what does Positive Acceleration Represent?

Answer 11

Acceleration, Velocity is Increasing

Question 12

On an Acceleration-Time Graph, what does Negative Acceleration Represent?

Answer 12

Deceleration, Velocity is Decreasing

Question 13

State what a Velocity-Time Graph Represents.

Answer 13

Change in Velocity over Time.

Question 14

State what the Gradient of a Velocity-Time Graph Represents.

Answer 14

Acceleration.

Question 15

State what the Area under a Velocity-Time Graph Represents.

Answer 15

Displacement.

Question 16

State what a Displacement-Time Graph Represents.

Answer 16

Change in Displacement over Time.

Question 17

State what the Gradient of a Displacement-Time Graph Represents.

Answer 17

Velocity.

Question 18

Define Instantaneous Velocity.

Answer 18

Velocity of an Object at a Specific Point in Time.

Question 19

Explain how to Calculate Instantaneous Velocity.

Answer 19

Drawing a Tangent on a Displacement-Time Graph at a Specific Point in Time and Calculating the Gradient.

Question 20

Define Average Velocity.

Answer 20

Velocity of an Object over a Specified Time Frame.

Question 21

State the Equation for Calculating the Average Velocity.

Answer 21

v = Final Displacement/Time

Question 22

Define Scalar Quantity.

Answer 22

A Quantity that only has Magnitude.

Question 23

Define Vector Quantity.

Answer 23

A Quantity that has Magnitude and Direction.

Question 24

State 4 Scalar Quantities.

Answer 24

-Distance
-Speed
-Mass
-Temeprature

Question 25

State 4 Vector Quantities.

Answer 25

-Displacement -Velocity -Acceleration -Force

Question 26

Define Resolving a Vector.

Answer 26

Splitting a Vector into Horizontal and Vertical Components.

Question 27

When Resolving Vectors, What part of the Diagram equals Magnitude?

Answer 27

The Resultant Vector

Question 28

When Resolving Vectors, What part of the Diagram equals Direction?

Answer 28

Angle

Question 29

When Resolving initial Velocity into Vertical Components what equation is used.

Answer 29

Sin(Angle) x Initial Velocity

Question 30

When Resolving initial Velocity into Horizontal Components what equation is used.

Answer 30

Cos(Angle) x Initial Velocity

Question 31

Explain how to complete a Projectile Motion Calculation for Maximum Height. (2)

Answer 31

-Resolve the Initial Velocity into the Vertical Component. -Calculate Distance by using: v^2=u^2 + 2as.

Question 32

Explain how to complete a Projectile Motion Calculation for Time in the Air. (3)

Answer 32

-Resolve the Initial Velocity into the Vertical Component. -Calculate Time by using: v=u+at. -Multiply answer by 2 (up/down).

Question 33

Define Free-Body Diagram.

Answer 33

A Diagram that shows all of the Forces acting upon an Object.

Question 34

Define Newton's 1st Law.

Answer 34

An Object at a Constant Velocity will remain at a Constant Velocity unless Acted on by a Resultant Force.

Question 35

Define Newton's 2nd Law.

Answer 35

Resultant Force =ma

Question 36

Define Resultant Force.

Answer 36

The Sum of all Forces acting on an Object.

Question 37

State whether a Resultant Force is Scalar or Vector Quantity.

Answer 37

Vector Quantity.

Question 38

In Newton's Second Law, which Component is always kept Constant?

Answer 38

Mass

Question 39

In Newton's Second Law, which Component is always in the Same Direction as the Resultant Force?

Answer 39

Acceleration

Question 40

Define Terminal Velocity. (3)

Answer 40

-The Maximum Velocity an Object can Achieve. -Frictional and Driving Force are Balanced. -No More Acceleration Occurs.

Question 41

Explain how a Skydiver reaches Terminal Velocity. (3)

Answer 41

-As they Leave the Plane, they Accelerate, beacuse of their Weight, is Greater than the Air Resistance acting on them. -As Speed Increases, so does the Magnitude of the Air Resistance Increases. -This Occurs until Weight and Air Resistance become Equal.

Question 42

Define Gravitational Field Strength.

Answer 42

Force per Unit Mass exerted by a Gravitational Field on an Object.

Question 43

State the Equation for Calculating Gravitational Field Strength.

Answer 43

g = F/m

Question 44

Define Weight.

Answer 44

The Force of Gravity on an Object.

Question 45

State the Equation for Calculating Weight.

Answer 45

W = mg

Question 46

Define Newton's 3rd Law.

Answer 46

For Each Force experienced by an Object, the Object Exerts an Equal and Opposite Force.

Question 47

A pair of Forces in Newton's 3rd Law must be what 4 things?

Answer 47

-Equal in Magnitude -Opposite in Direction -Acting on Different Bodies -The Same type of Force.

Question 48

In Newton's 3rd Law, why does an Object Move when a Force is Exerted?

Answer 48

It has a smaller Mass.

Question 49

State what happens to an Object in Unstable Equilibrium.

Answer 49

It will continue to fall away from its' Original Position.

Question 50

Define Momentum.

Answer 50

The Product of an Object's Mass and Velocity.

Question 51

State the Equation for Calculating Momentum.

Answer 51

p = mv

Question 52

Define the Principle of Conservation of Momentum.

Answer 52

In any Collision, the total Momentum of the Colliding Bodies remains Constant providing there are no External Forces acting on the Bodies.

Question 53

Define a Moment of a Force.

Answer 53

The Turning Effect about a Particular Pivot.

Question 54

State the Equation for Calculating a Moment.

Answer 54

Force x Perpendicular Distance to the Line of Action of the Force from the Point.

Question 55

Define the Principle of Moments.

Answer 55

For an Object to be in Equilibrium, the Sum of Anticlockwise and Clockwise Moments about a Pivot must be Equal.

Question 56

Define Centre of Mass.

Answer 56

It is the Point through which the total Mass of the Object is said to Act.

Question 57

Define Centre of Gravity.

Answer 57

The Point at which Gravity apears to Act.

Question 58

State 2 things Required for an Object's Stability.

Answer 58

-Low Centre of Gravity -Wide Base

Question 59

State what happens to an Object in Stable Equilibrium.

Answer 59

It will fall back to its' Original Position.

Question 60

State what happens to an Object in Neutral Equilibrium.

Answer 60

It will remain in Equilibrium

Question 61

Define Recoil.

Answer 61

Momentum is Conserved when 2 Objects Explode apart.

Question 62

Define Work Done.

Answer 62

A Force applied over a Distance and it's the Energy Transferred in that Distance.

Question 63

State the Equation for Calculating Work Done.

Answer 63

W = F x Change in Distance.

Question 64

State how to Resolve a Force Horizontally.

Answer 64

W = Fs Cos0

Question 65

State how to Resolve a Force Vertically.

Answer 65

W = Fs Sin0

Question 66

Define Kinetic Energy. (2)

Answer 66

-The Energy an Object has due to its Motion. -It is the amount of Energy that would be Transferred from the Object when it Decelerates to rest.

Question 67

State the Equation for Calculating Kinetic Energy.

Answer 67

Ek = 1/2 mv^2

Question 68

Define Gravitational Potential Energy.

Answer 68

The Energy Gained by an Object when it is Raised by a Height in a Gravitational Field.

Question 69

State the Equation for Calculating Gravitational Potential Energy.

Answer 69

Egrav = mgh

Question 70

Define the Principle of Conservation of Energy.

Answer 70

States that Energy Cannot be Created or Destroyed.

Question 71

State the Equation for Calculating the Total Energy in a Closed System.

Answer 71

Total Energy In = Total Energy Out.

Question 72

Define Power.

Answer 72

The Rate of Energy Transfer.

Question 73

State the 2 Equations for Calculating Power.

Answer 73

P = E/t P = W/t

Question 74

Derive Watts into SI Units.

Answer 74

Js-1

Question 75

State the Equation for Calculating Energy Transferred.

Answer 75

E = P x Change in Time.

Question 76

Define Efficiency.

Answer 76

A Measure of how Efficiently a System Transfers Energy.

Question 77

State the 2 Equations for Calculating Efficiency.

Answer 77

Useful Energy/Power Output Total Energy/Power Input