5. Forces

Question 1

What is a scalar?

Answer 1

Quantities that are fully described by magnitude or size

Question 2

What are vectors?

Answer 2

Quantities that are fully described by both a magnitude and direction

Question 3

What is distance?

Answer 3

A scalar quantity that refers to ‘how much ground an object has covered’

Question 4

What is displacement?

Answer 4

A vector quantity that refers to ‘how far out of place an object is’

Question 5

What is magnitude?

Answer 5

Size

Question 6

How can vectors be drawn?

Answer 6

Using arrows

Question 7

Is time a vector or scalar quantity?

Answer 7

scalar

Question 8

Is force a vector or scalar quantity?

Answer 8

Vector

Question 9

Is friction a vector or scalar quantity?

Answer 9

Vector

Question 10

Is weight a vector or scalar quantity?

Answer 10

Vector

Question 11

Is displacement a vector or scalar quantity?

Answer 11

Vector

Question 12

Is distance a vector or scalar quantity?

Answer 12

Scalar

Question 13

Is density a vector or scalar quantity?

Answer 13

Scalar

Question 14

Is energy a vector or scalar quantity?

Answer 14

Scalar

Question 15

Is frequency a vector or scalar quantity?

Answer 15

Scalar

Question 16

Is mass a vector or scalar quantity?

Answer 16

Scalar

Question 17

Is power a vector or scalar quantity?

Answer 17

Scalar

Question 18

Is voltage a vector or scalar quantity?

Answer 18

Scalar

Question 19

Is volume a vector or scalar quantity?

Answer 19

Scalar

Question 20

What is the gradient on a distance-time graph?

Answer 20

Velocity

Question 21

What is the gradient on a velocity-time graph?

Answer 21

Acceleration

Question 22

What is the area under a velocity-time graph?

Answer 22

The distance

Question 23

What is acceleration?

Answer 23

When an object speeds up or changes direction

Question 24

What is the total area underneath a velocity-time graph?

Answer 24

The total distance travelled

Question 25

What is the unit of force?

Answer 25

Newtons, N

Question 26

Examples of contact forces?

Answer 26

* Friction * Air / Water resistance (drag) * Normal contact (reaction) * Tension * Upthrust

Question 27

Examples of non-contact forces?

Answer 27

* Gravity * Magnetic * Electrostatic

Question 28

What happens when the resultant force on an object is zero?

Answer 28

The object remains stationary or continues to move at a constant speed and in the same direction.

Question 29

What is Newton's 1st law of motion?

Answer 29

An object will remain at rest or at a constant velocity unless there is a resultant force acting on it.

Question 30

What is Newton's 2nd law of motion?

Answer 30

The acceleration of an object is directly proportional to the resultant force and inversely proportional to the objects mass.

Question 31

What is Newton's 3rd law of motion?

Answer 31

If object A exerts a force on object B, then object B exerts a force on object A which is equal and opposite.

Question 32

What is thinking distance proportional to?

Answer 32

Speed

Question 33

What is braking distance proportional to?

Answer 33

Speed2

Question 34

What is thinking distance?

Answer 34

The distance travelled during reaction time.

Question 35

What is braking distance?

Answer 35

The distance travelled while the brakes are applied.

Question 36

Why does thinking distance increase?

Answer 36

* the speed increases | * the reaction time increases eg. tiredness, distraction, taken drugs / alcohol

Question 37

When does braking distance increase?

Answer 37

If the initial speed increases or if the size of deceleration is less.

Question 38

Typical speed of walking?

Answer 38

1.5 m/s

Question 39

Typical speed of running?

Answer 39

12 m/s

Question 40

Typical speed of driving?

Answer 40

20 m/s

Question 41

Typical speed of flying?

Answer 41

200 m/s

Question 42

Speed of sound in air?

Answer 42

3x10 squared

Question 43

Speed of light?

Answer 43

3x10 to the 8

Question 44

What is the weight of an object?

Answer 44

The force of gravity on it

Question 45

How to convert from Kg to N?

Answer 45

x10

Question 46

When does an object reach constant velocity?

Answer 46

When the drag force is equal and opposite to its weight

Question 47

What is terminal velocity?

Answer 47

When an object reaches a constant velocity because the drag force is equal and opposite to its weight

Question 48

What happens to the drag force when an object is released in a fluid before its terminal velocity?

Answer 48

The drag force is less than its weight before it reachers terminal velocity

Question 49

What happens to acceleration when an object is released in a fluid after its terminal velocity?

Answer 49

It is equal to zero

Question 50

What happens to the resultant force on an object released in a fluid initially?

Answer 50

The resultant force is equal to its weight, initally

Question 51

When an object is falling, what does it initially accelerate at?

Answer 51

10 m/s2

Question 52

What are plastic objects?

Answer 52

Objects that do not regain their original shape when the forces deforming it are removed

Question 53

What are elastic objects?

Answer 53

An object that regains its original shape when the forces deforming it are removed It stores elastic potential energy when work is done on the object

Question 54

Does an elastic collision lose kinetic energy?

Answer 54

No

Question 55

What does Hooke's law state?

Answer 55

That the extension of a spring is in direct proportion with the force applied to it

Question 56

What is the spring extension?

Answer 56

New length - original length

Question 57

What does hooke's law only apply to?

Answer 57

Elastic materials

Question 58

What happens to a spring if the force added on the spring is larger?

Answer 58

It not longer obeys hooke's law and does not return to its original length

Question 59

What is elastic limit?

Answer 59

The limit of proportionality (when hooke's law no longer applies)

Question 60

What is stopping distance?

Answer 60

Thinking distance + braking distance