Forces and Motion

Question 1

Name the force between two surfaces sliding over one another, that causes them to heat up and wear away.

Answer 1

Friction

Question 2

Name the force that pulls objects towards the centre of the Earth

Answer 2

Weight

Question 3

Name the force acting against any object that is moving through the Earth’s atmosphere.

Answer 3

Air resistance/drag

Question 4

Name the force pushing upwards on an object flying in the air.

Answer 4

Lift

Question 5

Name the force pushing upwards on an object in a fluid.

Answer 5

Upthrust

Question 6

Which force is a push caused by an engine (e.g. aircraft jet engine)?

Answer 6

Thrust

Question 7

What is the unit of force?

Answer 7

newton, N

Question 8

What instrument can we use to measure force in a lab?

Answer 8

newtonmeter

Question 9

If forces on an object are not balanced what do we have?

Answer 9

A resultant force

Question 10

If there is a resultant force on an object, what will happen?

Answer 10

Object will accelerate or decelerate

Question 11

Describe the motion of the car

Answer 11

Stationary

Question 12

Describe the motion of the car

Answer 12

Accelerating

Question 13

Describe the motion of the car

Answer 13

Decelerating

Question 14

Describe the motion of the car

Answer 14

Moving at constant speed

Question 15

Name the forces acting on the car

Answer 15

Up - normal contact force, Down - weight, forward - friction (look back to your notes if you are unsure why), Back - air resistance/drag

Question 16

What is the unit of weight?

Answer 16

newton, N

Question 17

what is the unit of mass?

Answer 17

kilogram, kg

Question 18

What is the formula that links mass and weight

Answer 18

weight = mass x gravitational field strength

Question 19

What is the Earth’s gravitational field strength?

Answer 19

10 N/kg (make sure you get the unit right!)

Question 20

What will happen to my mass if I go to the Moon?

Answer 20

stays the same

Question 21

What will happen to my weight if I go to the Moon?

Answer 21

It will change (decrease - the Moon has a smaller mass and radius that the Earth so the gravitational field strength is lower than on Earth)

Question 22

Describe the forces acting on a floating object

Answer 22

Weight = upthrust. These two forces are balanced. There is no resultant force

Question 23

For an object in a fluid, if weight > upthrust, what will happen?

Answer 23

The object will sink

Question 24

What causes upthrust?

Answer 24

There is a higher pressure at the bottom of the object than the top.

Question 25

List 2 characteristics of a streamlined shape

Answer 25

Rounded front Slowly tapering tail Smooth shape with no projections

Question 26

Name two ways to reduce resistive forces

Answer 26

Streamlining Lubrication (reduces friction between moving parts)

Question 27

How do we calculate speed

Answer 27

speed = distance / time

Question 28

If you know the speed of an object and time taken to travel a certain distance, how can you calculate distance?

Answer 28

distance = speed x time

Question 29

If you know the distance an object travelled and the speed it travelled at, how can you calculate the time it took?

Answer 29

time = distance / speed

Question 30

Describe the motion in different parts of the graph?

Answer 30

Question 31

The image shows a distance-time graph. Describe the motion of the object

Answer 31

It is accelerating (the graph is getting steeper, this means that the speed is increasing)

Question 32

The image shows a distance-time graph. Describe the motion of the object

Answer 32

It is decelerating (the steepness of the graph is decreasing, this means the speed is decreasing)

Question 33

The point a lever rotates about is known as....

Answer 33

Pivot

Question 34

In a lever, the distance between the pivot and where the force is applied is known as...

Answer 34

lever arm

Question 35

If I want to increase the turning effect of a lever, what 2 things could I change?

Answer 35

Increase the force applied Increase the length of the lever arm (i.e. distance from where the force is applied to the pivot)

Question 36

What is another word for turning effect?

Answer 36

moment

Question 37

What name is given to a type of joint that moves backwards and forwards (e.g. a knee)

Answer 37

Hinge

Question 38

What name is given to a type of joint that allows movement in a circle (e.g. a shoulder)

Answer 38

ball and socket

Question 39

What name is given to a type of joint that allows movement around an axis (e.g. an ankle)

Answer 39

pivot

Question 40

What is a pair of muscles that work in opposition to each other called?

Answer 40

antagonistic pair

Question 41

What happens to the shape of a muscle when it contracts?

Answer 41

It gets shorter and fatter

Question 42

What happens to the shape of a muscle when it relaxes?

Answer 42

It gets longer and thinner

Question 43

What links bone to bone?

Answer 43

Ligament

Question 44

What links bone to muscle?

Answer 44

Tendons

Question 45

Why do we have fluid in our joints

Answer 45

To reduce friction between bones