Chapter 09- Applications of Forces and Transfer of Energy Flashcards
To understand chapter 9 fully
How do Forces in Nature Affect Us Negatively?
The power of forces in nature causes natural disasters (e.g,
earthquakes, tsunamis, volcanic eruptions, tropical cyclones), affecting our daily lives.
How do Forces in Nature Affect Us Positively?
The power of forces in nature can also shape beautiful landscapes (e.g. mountains, valleys, limestone structures, arches etc).
What are forces?
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
What are contact forces
Forces that act through physical contact with the object
What are non-contact forces
Forces that act through non-physical contact with the object
Contact forces include
Frictional, normal, and elastic force
Non-contact forces include
gravitational force and magnetic force
What does weight mean
Gravitational pull exerted on an object
Which changes based on the location you go too with different gravitational pulls
Weight
What is the SI unit of weight, or forces in general
Newtons
What is used to measure weight
Spring balance
What are 5 things the transfer of energy between 2 different objects can do
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
What is the turning effect of a force
When a force helps to carry out actions with little force through pushing or pulling on a pivot
What is pressure
The effect of a force acting on an object
What can high pressure do
Penetrate an object easily
SI unit of pressure
Pascal
Pascal is also known as
N/m (squared)
Pressure formula:
Force divided by Area
Weight formula:
Mass times gravitational pull
Dams are thicker at the bottom because…
The water pressure is higher at the bottom of rivers
What is atmospheric pressure?
Atmospheric pressure is the pressure that the thick layer of air around earth acts on humans and other objects 6
How are tropical cyclones formed
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.
Why is a person able to drink liquids through the straws
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
How does a suction cup work
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
Formula for work done
Wd = Force x distance
SI unit for work done
Joules (J)
Define work done
Work done is the transfer of energy through the application of a force
For work to be done, which 3 conditons must be satisifed
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
How do you phrase energy conversion questions
Through an arrow showing the change
Most of the energy found on earth comes from ?
The sun
Fossil fuels are formed from what
The dead remains of organic matter buried in earth millions of years ago
Fossil fuel energy conversion
CPE -> TE -> KE -> EE
Impacts of fossil fuel burning
1)More CO2 in the air
2)More heat trapped in the atmosphere
3)Global warming
4)Climate change and acidification of ocean
Energy conversion of solar energy
light energy -> electrical energy
Pros and cons of solar energy
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
What is hydroelectric energy?
It is energy generated by turbines when moving waters power them
Energy conversion of hydroelectric energy
GPE -> KE -> KE -> EE
Pros and cons of hydroelectric energy
Pros: Produce very little greenhouse gases
Cons: Reservoirs might flood places behind the dam
Define wind energy
Converting energy from the wind to electrical energy
Energy conversion of wind energy
KE -> KE -> EE
Cons of wind energy
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
Define Geothermal energy
Geothermal energy is heat stored in earth, harnessed to generate electrical energy
Energy conversion of geothermal energy
TE -> KE -> KE -> EE
Cons of geothermal energy
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
Define biofuels
Biofuels are energy converted through animal waste or plant products that humans are unable to eat
Energy conversion of Biofuels
CPE -> TE -> KE
Pros and Cons of biofuels
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
Define Nuclear energy
Energy obtained through the nucleus of an atom through nuclear reactions then converted to electrical energy
Nuclear energy energy conversion
NE -> TE -> KE -> EE
Pros and cons of nuclear energy
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
