Forces

Question 1

What do Scalar quantities have ?

Answer 1

Magnitude only.

Question 2

What do Vector quantities have?

Answer 2

Magnitude (size ) and direction

Question 3

What can a Vector quantity be represented by ?

Answer 3

An arrow
The length represents magnitude.
The direction represents the direction of the force

Question 4

What are contact forces ?

Answer 4

When 2 or more forces are physically touching.

Question 5

Examples of a contact force ?

Answer 5

Friction, Air resistance, Tension

Question 5

What are non-contact forces

Answer 5

When 2 forces exert a force onto eachother but are physically seperated.

Question 6

What is weight ?

Answer 6

The force acting on a object due to gravity?

Question 6

Examples of a Non-contact force ?

Answer 6

Gravitational force, Electrostatic force and Magnetic force.

Question 7

What affects weight?

Answer 7

The gravitational field strength of where the object is?

Question 8

What is weight measured in?

Answer 8

Newtons

Question 9

What is mass measured in?

Answer 9

Kilograms

Question 10

What is gravitational field strength measured in ?

Answer 10

Newtons/ kilogram

Question 11

What can weight be measured using?

Answer 11

A calibrated spring-balance.

Question 12

What is a Resultant Force?

Answer 12

When a number of forces are replaced by a single force, which has the same effect as the original forces put together

Question 13

Which diagrams show Resultant forces, horizontally and vertically ?

Answer 13

Free Body Diagrams

Question 14

What is Work Done?

Answer 14

When a force causes an object to move through a distance or causes a displacement in the object.

Question 15

What is force measured in?

Answer 15

Newtons

Question 16

What is distance (S) measured in?

Answer 16

Metres

Question 17

What is extension directly proportional to ?

Answer 17

Force applied

Question 18

What is the limit of Proportionality?

Answer 18

When the extension is no longer proportional to the force applied.

Question 19

What is the spring constant measured in?

Answer 19

newtons per meter.

Question 20

What does it mean when a object is Elastically deformed?

Answer 20

When a object changes shape due to a force applied but returns to normal once it’s removed

Question 21

What does it mean when a object is Inelastically deformed ?

Answer 21

When a object chnage shape due to a force applied but does not return to normal once it’s removed.

Question 22

What is distance ?

Answer 22

It is how far an object has moved (scalar quantity)

Question 23

What is displacement ?

Answer 23

It is the distance of how far a object has moved measured in a straight line from the start to the ending point + the direction of that line. ( Vector quantity)

Question 24

Does speed involve direction (Scalar) ?

Answer 24

No it doesn't.

Question 25

Which factors affect the speed of a person or object?

Answer 25

Age, Terrain, Fitness and distance travelled.

Question 26

What are the typical speed values?

Answer 26

Walking- 1.5 m/s Running- 3 m/s Cycling- 6 m/s

Question 27

Is the speed of a moving object constant ?

Answer 27

No, when people walk and run or travel in a car, their speed is constantly changing.

Question 28

What is the unit for time?

Answer 28

Seconds

Question 29

What is the unit for speed?

Answer 29

Meters per Second

Question 30

What is Velocity?

Answer 30

It is speed in a given direction

Question 31

How can you calculate the speed of a object?

Answer 31

From the gradient of it's distance- time graph.

Question 32

How do you calculate the gradient of distance-time graph?

Answer 32

By drawing a tangent

Question 33

How can you calculate the speed from a velocity- time graph?

Answer 33

From the area underneath the graph, a triangle.

Question 34

What happens to an object in a fluid ?

Answer 34

It initially accelerates due to the force of gravity, but eventually it's resultant force will be 0 and it will be at Terminal Velocity.

Question 35

What is Newton's First Law ?

Answer 35

If the Resultant Force acting on an object is 0... if the object is stationary, it will remain stationary. if the object is moving, it will remain at the same speed and going in the same direction ( same velocity)

Question 36

What can you apply Newton's First Law to?

Answer 36

In an exam, you can explain the motion of objects moving at a uniform velocity and objects where the speed/direction changes.

Question 37

What is Inertia?

Answer 37

The tendency of objects to continue in their state of rest or of uniform motion.

Question 38

What is Newton's Second Law ?

Answer 38

The acceleration of an object is proportional to the Resultant Force acting on the object, and is inversely proportional to it's mass.

Question 39

What is Newton's Third Law ?

Answer 39

Whenever 2 forces, interact the forces they exert on each other are equal and opposite. ( Can be used in Equilibrium questions)

Question 40

What is the Stopping Distance?

Answer 40

It is the sum of the distance the vehicle travels during the driver's reaction time (Thinking Distance) and the distance it travels under breaking force (Breaking Distance)

Question 41

What can a driver's reaction time be affected by?

Answer 41

Tiredness Drugs Alcohol.

Question 42

What can a driver's braking distance be affected by?

Answer 42

Wet or Icy Roads Poor Brake conditions Poor Tyre condition

Question 43

What happens when a force is applied to the brakes?

Answer 43

The work done by the friction force between the breaks and wheel reduce the KINETIC ENERGY within the car, and transfers it to the car's THERMAL ENERGY STORE and the car's temperature increases.

Question 44

What's the relationship between Braking Forces and Speed ?

Answer 44

The greater the speed of a Vehicle, the greater the braking force needed to stop the Vehicle in a certain distance.

Question 45

What can happen if too much force is applied to the breaks/ Large deacceleration?

Answer 45

The brakes may overheat or it could cause a loss of control.

Question 46

Braking force and deacceleration?

Answer 46

The larger the braking force, the larger the deacceleration.

Question 47

What is the conservation of Momentum?

Answer 47

The total momentum before an event is equal to the total momentum after the event.

Question 48

When can you talk about momentum in exams?

Answer 48

In questions that discuss collisions and as a model.

Question 49

What is momentum?

Answer 49

It is a property of each moving object an it's the object's mass multiplied by it's velocity.