topic 5 Flashcards Preview

gcse physics year 11 > topic 5 > Flashcards

Flashcards in topic 5 Deck (37):
1

what is force

a vector quantity

2

what do vector quantities have

A magnitude or direction

3

4 examples of vector quantities

-Force
-Acceleration
-Momentum
-displacement

4

what are scalar quantities

physical quantities that have magnitude but no direction

5

5 examples of scalar quantities

-Speed
-Mass
-Time
-Temp
-Distance

6

what does the length of the vector quantity show

its magnitude

7

what does the arrow in vector quantities show

the direction of the quantity

8

what quantity is speed

scalar

9

what are all forces

contact or non-contact forces

10

what is a contact force

when two objects have to be touching for a force to act

11

what is a non-contact force

if the objects do not need touching for the force to act

12

what is an interaction pair

a pair of forces that are equal and opposite and act on two interacting objects

13

(Momentum) the greater the mass of an object or the greater its velocity ...

The momentum the object has

14

What quantity is momentum

A vector quantity- it has size and direction

15

Momentum (kg m/s) =

Mass (kg) X velocity (m/s)

16

What is “conservation of momentum”

In a closed system the total momentum before an event is the same as after the event

17

Stopping distance =

Thinking distance + braking distance

18

What is your thinking distance affected by?

-speed
-your reaction time

19

What is braking distance affected by?

-speed
-weather
-condition of tyres
-how good the brakes are

20

What is the breaking distance of 30mph?

14 m

21

What is the braking distance of 60 mph?

55 m

22

What is the braking distance of 70mph?

75 m

23

The work done between the brakes and the wheels transfers energy from the ...

Kinetic energy stores of the wheels to the thermal energy stores of the brakes

24

What does a larger braking force mean

A larger deceleration

25

The faster a vehicle is going ...

The more energy it has in its kinetic stores, so the more work needs to be done to stop it

26

What is inertia

The tendency to continue in the same state of motion

27

What does an objects inertial mass measure

How difficult it is to change the velocity of an object

28

What is Newtons third law

When 2 objects interact, the forces they exert in each other are equal and opposite

29

What does newtons first law state

That a resultant force is needed to make something start moving, speed up or slow down

30

What will a non-zero resultant force always produce

Acceleration or deceleration in the direction of the force

31

The larger the resultant force acting on an object ..

The more the object accelerates

32

Force and acceleration are ..

Directly proportional

33

What is acceleration inversely proportional to

The mass of the object

34

What 5 forms can acceleration take

-stopping
-speeding up
-slowing down
-changing direction
-starting

35

What is drag

The resistance you get in a fluid (a gas or a liquid(

36

Give an example of a type of drag

Air resistance

37

What is the important factor in reducing drag

Keeping the shape of the object streamlined