YEAR 9 - Topic 4 - Movement, terminal velocity, newtons 1st and 2nd law and Forces???

Question 1

What types of forces are there?

Answer 1

• weight
• reaction
• drag
• upthrust
• electrostatic
• magnetic
• tension
• thrust

Question 2

What are examples of non contact forces?

Answer 2

• weight
• electrostatic
• magnetic

Question 3

What are examples of contact forces?

Answer 3

• reaction
• drag
• upthrust
• tension
• thrust

Question 4

What can a force do to an object?

Answer 4

Change it’s:

• speed
• direction
• shape

Question 5

What does this force mean?

Weight

Answer 5

Weight is the force due to mass being in a gravitational field.

Question 6

What does this force mean?

Reaction

Answer 6

Reaction is the force of a surface that it applies back up when a weight presses down on it.

Question 7

What does this force mean?

Drag

Answer 7

Drag is both friction and air resistance. It occurs when two surfaces rub together, this force acts in the opposite direction to the motion and tries to slow the object down.

Question 8

What does this force mean?

Upthrust

Answer 8

Upthrust is often called lift. It refers to the upwards force in liquids (like a boat floating) and in gases (like aeroplane wings).

Question 9

What does this force mean?

Electrostatic

Answer 9

Electrostatic is the force betweeen two electrically charged objects/ particles.

Question 10

What does this force mean?

Magnetic

Answer 10

Magnetic is the force between two magnets.

Question 11

What does this force mean?

Tension

Answer 11

Tension is the force in a rope or cable.

Question 12

What does this force mean?

Thrust

Answer 12

Thrust is the forward force in a rocket to speed it up.

Question 13

What is resultant force?

Answer 13

Resultant force is the overall effect of all the forces acting on an object. It takes into account direction and size.

Question 14

What is Newton’s 1st law?

Answer 14

Newton’s first law is the theory that if there is no resultant force (all the forces are balanced), then there is no change in speed. This means an object either stays still or moves at a steady speed.

Question 15

What is Newton’s 2nd law?

Answer 15

Newton’s 2nd law is the theory that if forces are unbalanced, and there is a resultant force, then the object will either accelerate or decelerate. This means that there will be a change in speed.

Question 16

What is the acceleration equation?

Answer 16

Force = mass X acceleration
            /\ 
         / Fr \
      /-——\ 
   /   m X a   \
  —————

Question 17

How do you remember the acceleration triangle?

Answer 17

My Funny Aunt

Question 18

What is acceleration?

Answer 18

Acceleration is the change in velocity every second.

Question 19

What is the difference between mass and weight?

Answer 19

Mass is the amount of matter in a substance, linked to the number of particles. Weight is the force on mass due to being in a gravitational field.

Question 20

What is mass?

Answer 20

Mass is the amount of matter there is in a substance linked to the amount of particles there are.

Question 21

What is weight?

Answer 21

Weight is the force on a mass due to a gravitational field.

Question 22

How do you work out drag?

Answer 22

Drag = weight - resultant force

Question 23

Which of the two can change?

Mass and weight

Answer 23

Weight scan change as it depends on the strength of the gravity.

Question 24

What is gravity strength on earth?

Answer 24

10N/kg

Question 25

What is the gravity strength on the moon?

Answer 25

1.62 N/Kg

Question 26

What is the mass, weight and GFS equation?

Answer 26

``` Weight = mass X GFS / \ / w \ /———\ / m X GFS \ —————- ```

Question 27

What factors affect the size of friction?

Answer 27

- the type of surface | - mass of the object

Question 28

How do you work out the overall stopping distance?

Answer 28

Thinking distance + braking distance

Question 29

How do you work out thinking distance?

Answer 29

Thinking distance = speed X reaction time

Question 30

What is the average reaction time?

Answer 30

0.6 seconds

Question 31

What can slow down your reaction time?

Answer 31

- alcohol/drugs - Fatigue - hazard perception ability - vision issues

Question 32

What is the thinking distance?

Answer 32

Thinking distance is the distance travelled while reacting to a stimulus, until the breaks are used.

Question 33

What is breaking distance?

Answer 33

Breaking distance is the distance travelled by a vehicle whilst braking.

Question 34

What factors affect braking distance?

Answer 34

- road surface - weather conditions - vehicle mass - speed of vehicle

Question 35

How do you work out braking distance?

Answer 35

Mu2 —— 2Fr Mass X initial speed squared ————————————- 2 X resultant force

Question 36

How does thinking distance increase?

Answer 36

Thinking distance increases linearly

Question 37

How does braking distance increase?

Answer 37

Braking distance increases squared.

Question 38

What does air resistance depend on?

Answer 38

Air resistance depends on surface area and speed.

Question 39

Do skydivers ever go up?

Answer 39

NO! (Other than in the plane)

Question 40

What is terminal velocity?

Answer 40

A terminal velocity is where the air resistance balances out the velocity. This means that the skydiver doesn’t accelerate any more until the surface area changes.