Chapter 3 - Forces And Movement

Question 1

WHAT IS A FORCE?

Answer 1

A pull or a push

Question 2

WHAT IS MOVEMENT?

Answer 2

Changing position or part of an object.

Question 2

Forces are all around you. Can you see them?

Answer 2

You cannot see them.
You can only see what they do.
They are everywhere.
They cause movement.
They can make things go slower or faster.

Question 3

Name 4 forces.

Answer 3

Gravity
Muscular
Buoyancy
Friction

Question 4

WHAT IS GRAVITY?

Answer 4

The pull of objects toward a planet.

PULLING FORCE.

Question 5

EXAMPLES OF GRAVITY

Answer 5

• an apple falling from a tree
• a ball rolling down a hill
• Taya walking on earth instead of floating
• a child going down a slide
• food sitting on a table

Question 6

WHAT IS MUSCULAR FORCE?

Answer 6

The pull of muscles on bones that allows us to move in different directions.

MOVEMENT FORCE

Question 7

EXAMPLES OF MUSCULAR FORCE

Answer 7

• walking
• lifting an object
• bouncing a ball
• riding your bike
• dancing
• typing on a computer

Question 8

WHAT IS BUOYANCY?

Answer 8

Upward pushing force of water and other liquids on objects.
Example: Your body pushes down on the water and the water pushes up on you to keep you afloat.

PUSHING FORCE

Question 9

EXAMPLES OF BUOYANCY

Answer 9

• a boat floating
• an apple floating in a bucket
• a buoy in the lake floating

Question 10

WHAT IS FRICTION?

Answer 10

The rubbing ,sliding and pushing of two objects against each other.

SLIDING FORCE

Question 11

EXAMPLES OF FRICTION

Answer 11

• walking (feet and floor)
• rubbing your hands together
• skiing (skis and snow)
• ironing (clothes and iron)
• driving a car or riding a bike (tires and road) - your tires are not smooth so that they can grip the surface better

Question 12

FRICTION: Is there more or less friction on rough surfaces?

Answer 12

= more friction

Example: Driving on a dry road compared to a wet road.

Question 13

FRICTION: Is there more or less friction on smooth surfaces?

Answer 13

= less friction

Example: slide

Question 14

Why do we want to increase friction?

Answer 14

To make things less slippery and in some cases safer.

Question 15

Why do we want to decrease friction?

Answer 15

Too much rubbing can wear out things.
To allows things to rotate easily.
Less energy is used.

Question 16

Do some situations have more than one force involved?

Answer 16

YES

Question 17

MULTIPLE FORCES AT WORK - EXAMPLES

Answer 17

Canoe moving in the water - buoyancy and friction and gravity.

Question 18

WHAT ARE 2 FORCES THAT CAN PUSH OR PULL?

Answer 18

MAGNETIC FORCE and STATIC FORCE

Question 19

WHAT IS A MAGNETIC FORCE?

Answer 19

The pull of some metal objects by a magnet OR the pushing away of two like poles.

Objects with same charge push away (REPEL).
Objects with different charges pull toward each other.

Question 20

WHAT IS A STATIC ELECTRIC FORCE?

Answer 20

A push or pull caused by a buildup of charged particles.

Objects with the same charge push away.
Objects with different charges pull toward each other.

Question 21

WHAT CAN A FORCE DO?

Answer 21

• can make an object move faster
• can make an object move slower
• can change the direction that an object is moving in
• can change the shape of an object

Question 22

What is DIRECTION?

Answer 22

Which way an object is moving.

It could be right, left, north, south, east, west, up, down, forwards, backwards, etc.

Question 23

WHY DO ENGINEERS DEVELOP SAFETY DEVICES?

Answer 23

• moving objects want to keep moving unless a force acts on them
• to slow things down or stop them from moving safety devices are used

Question 24

EXAMPLES OF SAFETY DEVICES

Answer 24

SEATBELT

• when in a car, your body keeps moving with the car
• if the car stops suddenly, your body will keep moving unless a force stops it
• a seatbelt stops you from continuing to move forward

Question 25

OTHER SAFETY DEVICES

Answer 25

• parachute
• tying a boat to the dock with a rope
• harness when climbing things
• harness when bungee jumping
• airbags

Question 26

What is SPEED?

Answer 26

How fast an object is going.

Question 27

Do we need contact?

Answer 27

• Some forces act through direct contact with an object (Example: if a parachute wasn’t attached to a jumper, he would fall to the ground).
• Some forces do not need contact to act (Example: the jumper from the plane has gravity acting on him to pull him to the ground with no contact at all.

Question 28

WHAT 3 FORCES NEED CONTACT:

Answer 28

• muscular
• friction
• buoyancy

Question 29

WHAT 3 FORCES DO NOT NEED CONTACT:

Answer 29

• magnetic
• gravity
• static electric

Question 30

NAME SOME FORCES IN NATURE AND HUMAN ENVIRONMENTS.

Answer 30

• erosion
• landslides
• lightning
• tidal waves

Question 31

FORCES IN NATURE: EROSION

What is erosion?

Answer 31

• when gravity causes water to flow downwards

- the water moves soil and rocks

Question 32

How do humans speed up erosion?

Answer 32

• cutting down trees
• removing shrubs
• removing plants
• having too many animals on farmland

Question 33

What happens to soil when it is lost through erosion?

Answer 33

• it pollutes rivers, lakes, and water systems
• changes the land
• changes our food supply

Question 34

Can erosion affect structures on the land?

Answer 34

Yes. Buildings can become unstable as the soil/sand is washed away.

Question 35

What is a landslide?

Answer 35

-when gravity causes large sections of land to slide downward across other land.

Question 36

How are landslides triggered? What causes them?

Answer 36

• rain
• floods
• earthquakes
• other natural events (e.g., hurricanes)
• human activities (e.g., put in lawns, gardens, roads, houses)

Question 37

What are the negative (bad) effects of landslides?

Answer 37

• flooding
• pollute water
• destroy trees and plants
• moves rocks, vegetation which drastically changes the landscape
• animals habitats are ruined
• animals are killed
• houses, roads (transportation), and utilities (hydro electricity/water supply) are destroyed