Forces And Speed

Question 1

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

Answer 1

Weight

Question 2

Name the force acting against any object that is moving through the Earths atmosphere.

Answer 2

Air resistance/ drag

Question 3

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

Answer 3

Lift

Question 4

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

Answer 4

Upthrust

Question 5

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

Answer 5

Thrust

Question 6

What is the unit of force?

Answer 6

Newton, N

Question 7

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

Answer 7

Newton meter

Question 8

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

Answer 8

A resultant force

Question 9

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

Answer 9

Object will accelerate or decelerate

Question 10

Name the forces acting on the car

Answer 10

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

Question 11

What is the unit of weight?

Answer 11

newton, N

Question 12

what is the unit of mass?

Answer 12

Kg

Question 13

What is the formula that links mass and weight

Answer 13

weight = mass x gravitational field strength

Question 14

What is the Earth’s gravitational field strength?

Answer 14

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

Question 15

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

Answer 15

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 16

Describe the forces acting on a floating object

Answer 16

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

Question 17

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

Answer 17

The object will sink

Question 18

What causes upthrust?

Answer 18

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

Question 19

List 2 characteristics of a streamlined shape

Answer 19

“Rounded front
Slowly tapering tail
Smooth shape with no projections”

Question 20

Name two ways to reduce resistive forces

Answer 20

“Streamlining
Lubrication (reduces friction between moving parts)”

Question 21

How do we calculate speed

Answer 21

speed = distance / time

Question 22

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

Answer 22

distance = speed x time

Question 23

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

Answer 23

time = distance / speed

Question 24

The point a lever rotates about is known as….

Answer 24

Pivot

Question 25

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

Answer 25

Lever arm

Question 26

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

Answer 26

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

Question 27

What is another word for turning effect?

Answer 27

Moment

Question 28

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

Answer 28

Hinge

Question 29

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

Answer 29

Ball and socket

Question 30

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

Answer 30

Pivot

Question 31

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

Answer 31

Antagonistic pair

Question 32

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

Answer 32

It gets shorter and fatter

Question 33

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

Answer 33

It gets longer and thinner

Question 34

What links bone to bone?

Answer 34

Ligament

Question 35

What links bone to muscle?

Answer 35

Tendons

Question 36

Why do we have fluid in our joints

Answer 36

To reduce friction between bones