Forces

Question 1

Describe scalar quantities ?

Answer 1

Scalar quantity’s have magnitude (amount) only

Distance is taken into account

Question 2

Describe vector quantity’s ?

Answer 2

Vectors quantities have magnitude (amount) and direction

Displacement is taken into account not distance due to direction

Question 3

What is a contact force simple explanation ?

Answer 3

The objects are physically touching

Question 4

What is non-contact force simple explanation ?

Answer 4

The objects do not need to touch are physically separated

Question 5

Example of scalar quantity’s ?

Answer 5

Speed, energy, power, pressure, temperature

Question 6

Examples of vector quantities ?

Answer 6

Velocity, drag, thrust, force, momentum and acceleration

Question 7

Examples of non contact forces ?

Answer 7

Magnetic, electrostatic and gravitational

Question 8

Examples of contact forces ?

Answer 8

Weights, friction, air resistance and normal contact

Question 9

What is resultant force ?

Answer 9

The sum of all forces acting on a body

It’s decides the speed and direction of the body

Question 10

Describe force (3 actions) ?

Answer 10

Force is a push or a pull on an object that causes it to
1) change speed
2) change direction
3) change shape

Question 11

Why is friction a necessary evil ?

Answer 11

Example :
Friction can cause wear of tires but without friction the car will slide

Question 12

What does the weight of a force depend on (gravitational field strength) ?

Answer 12

The weight of an object depends on its gravitational field strength at the point where the object is.

Question 13

What way can you measure weight ?

Answer 13

Newtonmeter

Question 14

What is net force ?

Answer 14

Forces are balanced (0N)

Body will not move

Question 15

What are moments ?

Answer 15

The turning affect of force on an object

The shorter the effort from the pivot mean that the more load can be lifted.

Example :

The shorter the stick is on the pivot the more rocks it can lift because more momentum can be gained on smaller effort

Question 16

Give 3 examples of levers ?

Answer 16

1) scissors
2) spanner
3) bottle opener

Question 17

What do gears do ?

Answer 17

They transmit the turning effect of force

the bigger the gear means more radius so greater turning affect

Question 18

What does a low gear do ?

Answer 18

For example on a bike a low gear moves at a low speed with higher turning affect

Question 19

What does a high gear do ?

Answer 19

For example on a bike a high gear moves at a fast speed with lower turning affect

Question 20

What is velocity ?

Answer 20

Speed in a given direction

Question 21

What is the differences of an object in pressure at different depths of a liquid ?

Answer 21

A submerged object will have a greater pressure on the bottom surface than the top.

(Varies with depth) due to more water molecules

This creates a resultant force upwards called up thrust.

Just like a human the deeper under water we go the more pressure we experience.

Question 22

How do you calculate an object that moves in a straight line ?

Answer 22

A distance speed time graph

Question 23

What does Newton’s first law of motion say about motion of an object ?

Answer 23

It says that a resultant force is required to change the motion of an object because if a moving object had no resultant force it would carry on moving with the same velocity

And if a stationary object had no resultant force it would stay stationary

No resultant force means no change

Question 24

What does Newton’s second law of motion say about motion of an object ?

Answer 24

Newton’s second law says if they’re is a resultant force on an object it will cause it to accelerate

Resultant force = anything but zero

Depending on the original position/movement of the object the result force could cause it to go faster in a certain direction

Or completely stop due to the force in the other way

Question 25

What is inertia ?

Answer 25

It’s the idea that unless an object is acted on it will not change motion

Question 26

What does Newton’s third law of motion say about an object ?

Answer 26

When two objects interact the forces they exert on each other are equal and opposite For example = If you push a box with 100N the box will have an equal 100N force on you, they would just be acting on opposite directions and depending on the mass of you or the box one would move

Question 27

What is the stopping distance equal to ?

Answer 27

Stopping distance = thinking distance + braking distance

Question 28

What is the thinking distance ?

Answer 28

How far the car travels while the driver see’s the object thinks and apples the brakes

Question 29

What two things affect thinking distance ?

Answer 29

1. Speed of vehicle 2. Reaction time

Question 30

Why does speed affect your thinking distance ?

Answer 30

Because the faster your travelling the further you’re travelling

Question 31

What things affect the reaction time of someone ?

Answer 31

Tiredness Drinking Drugs Distracted

Question 32

What is the braking distance ?

Answer 32

Distance taken to stop under the force of brakes

Question 33

What are important factors that affect braking distance ?

Answer 33

Speed of vehicle Mass of vehicle Condition Of the brakes Traction between the car and road

Question 34

How does pressure affect braking distance ?

Answer 34

The more pressure means the shorter the braking distance will be the longer the braking distance will be less pressure vice versa

Question 35

What things affect the traction between car and road ?

Answer 35

Wet road Icy road Lack of grip on tires

Question 36

What does the affect of speed have on a graph of stopping distance ?

Answer 36

The faster your travelling the longer it will take you to stop

Question 37

What is the conservation of momentum principe ?

Answer 37

The total momentum before is = to the total momentum after in a closed system A positive number means right A negative number means left