Chapter 09- Applications of Forces and Transfer of Energy

Question 1

How do Forces in Nature Affect Us Negatively?

Answer 1

The power of forces in nature causes natural disasters (e.g,
earthquakes, tsunamis, volcanic eruptions, tropical cyclones), affecting our daily lives.

Question 2

How do Forces in Nature Affect Us Positively?

Answer 2

The power of forces in nature can also shape beautiful landscapes (e.g. mountains, valleys, limestone structures, arches etc).

Question 3

What are forces?

Answer 3

Forces are the interactions between two objects

or

A force the push or pull on an object with mass causes it to
change its velocity

Question 4

What are contact forces

Answer 4

Forces that act through physical contact with the object

Question 5

What are non-contact forces

Answer 5

Forces that act through non-physical contact with the object

Question 6

Contact forces include

Answer 6

Frictional, normal, and elastic force

Question 7

Non-contact forces include

Answer 7

gravitational force and magnetic force

Question 8

What does weight mean

Answer 8

Gravitational pull exerted on an object

Question 9

Which changes based on the location you go too with different gravitational pulls

Answer 9

Weight

Question 10

What is the SI unit of weight, or forces in general

Answer 10

Newtons

Question 11

What is used to measure weight

Answer 11

Spring balance

Question 12

What are 5 things the transfer of energy between 2 different objects can do

Answer 12

1) Move a stationary object
2) Change the speed of an object
3) Change the direction in which an object moves
4) Stop a moving object
5) Changes in size and shape

Question 13

What is the turning effect of a force

Answer 13

When a force helps to carry out actions with little force through pushing or pulling on a pivot

Question 14

What is pressure

Answer 14

The effect of a force acting on an object

Question 15

What can high pressure do

Answer 15

Penetrate an object easily

Question 16

SI unit of pressure

Answer 16

Pascal

Question 17

Pascal is also known as

Answer 17

N/m (squared)

Question 18

Pressure formula:

Answer 18

Force divided by Area

Question 19

Weight formula:

Answer 19

Mass times gravitational pull

Question 20

Dams are thicker at the bottom because…

Answer 20

The water pressure is higher at the bottom of rivers

Question 21

What is atmospheric pressure?

Answer 21

Atmospheric pressure is the pressure that the thick layer of air around earth acts on humans and other objects 6

Question 22

How are tropical cyclones formed

Answer 22

Tropical cyclones are formed through differences in air pressure. In tropical climates, when the sun evaporates a water body and causes clouds to form above the sea, it will cause a region of lower pressure, causing giant winds to form due to the surrounding areas with higher atmospheric pressure, thereby causing cyclones.

Question 23

Why is a person able to drink liquids through the straws

Answer 23

This is due to the fact that when air is taken out of the straws, the air pressure inside will then be lower than the surrounding air pressure, leading the higher atmospheric pressure to push the liquid back into the boys moouth

Pressure will always try to replenish itself till equilibrium is reached

Question 24

How does a suction cup work

Answer 24

Air is pushed out from within the suction cup, leading the air pressure inside the suction cup to decrease. This makes the atmospheric pressure high enough to hold the suction cup hooked into place

Question 25

Formula for work done

Answer 25

Wd = Force x distance

Question 26

SI unit for work done

Answer 26

Joules (J)

Question 27

Define work done

Answer 27

Work done is the transfer of energy through the application of a force

Question 28

For work to be done, which 3 conditons must be satisifed

Answer 28

1) A force is applied on the object 2) The object moves 3) The object moves in the same direction as the force that is applied on it

Question 29

How do you phrase energy conversion questions

Answer 29

Through an arrow showing the change

Question 30

Most of the energy found on earth comes from ?

Answer 30

The sun

Question 31

Fossil fuels are formed from what

Answer 31

The dead remains of organic matter buried in earth millions of years ago

Question 32

Fossil fuel energy conversion

Answer 32

CPE -> TE -> KE -> EE

Question 33

Impacts of fossil fuel burning

Answer 33

1)More CO2 in the air 2)More heat trapped in the atmosphere 3)Global warming 4)Climate change and acidification of ocean

Question 34

Energy conversion of solar energy

Answer 34

light energy -> electrical energy

Question 35

Pros and cons of solar energy

Answer 35

Pros: Solar energy can generate electricity without releasing air pollutants and greenhouse gasses Cons: The production of solar panels uses up lots of energy, and toxic waste could be released due to inadequate production of disposal of solar panels

Question 36

What is hydroelectric energy?

Answer 36

It is energy generated by turbines when moving waters power them

Question 37

Energy conversion of hydroelectric energy

Answer 37

GPE -> KE -> KE -> EE

Question 38

Pros and cons of hydroelectric energy

Answer 38

Pros: Produce very little greenhouse gases Cons: Reservoirs might flood places behind the dam

Question 39

Define wind energy

Answer 39

Converting energy from the wind to electrical energy

Question 40

Energy conversion of wind energy

Answer 40

KE -> KE -> EE

Question 41

Cons of wind energy

Answer 41

1) WInd energy requires large plots of land to be cleared (REDUCTION OF HABITATS) 2) Birds might be killed if they collide into the rotating fan blades 3) Noise pollution

Question 42

Define Geothermal energy

Answer 42

Geothermal energy is heat stored in earth, harnessed to generate electrical energy

Question 43

Energy conversion of geothermal energy

Answer 43

TE -> KE -> KE -> EE

Question 44

Cons of geothermal energy

Answer 44

Geothermal energy sites usually require the clearing of large plots of land, destroying habitats as a result. These sites could also release trace amounts of toxic waste to the public

Question 45

Define biofuels

Answer 45

Biofuels are energy converted through animal waste or plant products that humans are unable to eat

Question 45

Energy conversion of Biofuels

Answer 45

CPE -> TE -> KE

Question 46

Pros and Cons of biofuels

Answer 46

Pros: biofuels are sustainable and can be easily grown back. The carbon dioxide that is released through cars can be absorbed by biofuel plants Cons: Burning of biofuels releases greenhouse gasses into our atmosphere

Question 47

Define Nuclear energy

Answer 47

Energy obtained through the nucleus of an atom through nuclear reactions then converted to electrical energy

Question 47

Nuclear energy energy conversion

Answer 47

NE -> TE -> KE -> EE

Question 48

Pros and cons of nuclear energy

Answer 48

Pros: Clean energy, and requires less land to generate the same amount as the other energies Cons: Risk to health and safety of the community near the nuclear plants