Energy n Forces

Question 1

How do forces in nature affect us

Answer 1

1. They cause natural disasters that destroy buildings and roads which result in the loss of lives
2. They also help shape our physical environment

Question 2

Types of forces

Answer 2

1. Contact forces: Forces that act when an object is in contact with another
2. Non-contact forces: Forces that can act from afar and do not require contact.

Question 3

What is Frictional force

Answer 3

1. It is a contact force
2. Force that opposes the motion between two surfaces in contact.

Question 4

What are the advantages of Friction

Answer 4

1. We can walk on the ground without slipping
2. We can hold onto objects without dropping them

Question 5

What are the disadvantages of Friction

Answer 5

1. Causes wear and tear
2. Cause a waste of energy

Question 6

What is Gravitational force

Answer 6

1. It is a non-contact force
2. It is a force that attracts two objects toward each other
3. A planet that exerts gravitational force pulls an object toward its centre causing the object to have weight.

Question 7

Effects of Gravity

Answer 7

1. Causes the earth to orbit around the sun
2. Causes things to drop to the ground when we let go

Question 8

What is Magnetic Force

Answer 8

1. It is a non-contact force
2. It is a force that exerted between a magnet and a magnetic material or another magnet itself

Question 9

How to phrase attraction/repulsion

Answer 9

Attraction: When two unlike poles are brought close to each other, they pull together due to the magnetic force of attraction.
Repulsion: When two like poles are brought close together, they push away from each other due to the magnetic force of repulsion

Question 10

Application of Magnets in real-world context

Answer 10

1. Maglev trains.
2. The Maglev train slightly lifts up due to the magnetic force of repulsion.
3. This allows it to travel at higher speeds as It is not in contact with a surface, reducing friction between the track and the train

Question 11

Weight Characteristics

Answer 11

1. Weight is the amount of gravitational force acting on an object
2. Measured in Newtons (N)
3. Measuring instrument is Spring balance
4. Changes depending on the height you are at

Question 12

Mass characteristics

Answer 12

1. Mass is the amount of matter in an object
2. Measured in Grams or Kilograms (g/kg)
3. Measured by an electronic balance
4. It does not change depending on height you are at

Question 13

How to measure force

Answer 13

Spring balance and hook the object onto it and see how far the spring extends.

Question 14

What are the effects of forces

Answer 14

1. Forces can move a stationary object
2. Forces can stop a moving object
3. Forces can change the direction of a moving object
4. Forces can change the speed of a moving object
5. Forces change the shape and size of an object
6. Causes the turning effect

Question 15

Turning effect

Answer 15

Causes an object to move about a fixed point known as the pivot

Question 16

Formula for pressure

Answer 16

Force divided by surface area

Question 17

How to increase pressure

Answer 17

Decrease surface area or Increase the Force of the object.

Question 18

Applications of Pressure

Answer 18

1. Injection needle
2. Needs to be sharp so that the surface in contact with the skin is very small
3. With a strong force, it can easily penetrate the skin.

Question 19

Water pressure

Answer 19

A higher pressure acts on your body when you go deeper into the water

Question 20

Atmospheric pressure

Answer 20

1. the layer of particles push down on earth’s surface due to gravitation
2. The lower the object, the more atmospheric pressure acting on the object

Question 21

Straw atmospheric pressure concept

Answer 21

1. When the guy sucks on the straw some air is removed from the straw
2. The air pressure inside the straw decreases due to the lack of air particles
3. The higher atmospheric pressure in the bottle pushes the water down and into the straw

Question 22

Suction cup concept

Answer 22

1. When the cup is pushed against the wall, some air is pushed out
   from under the cup.
2. This causes the atomspheric pressure between the surface and the suction cup to decrease,
3. The higher surrounding atmospheric pressure presses on the cup and allows it to stay in place

Question 23

When is work done

Answer 23

1. Force is applied on an object
2. The object moves
3. The object moves in the same direction as the force applied on it

Question 24

What is total energy

Answer 24

1. Energy cannot be created or destroyed
2. The total energy is not lost but is converted to other forms of energy

Question 25

What are fossil fuels

Answer 25

1. They are fromed from the remains of dead plants and animals burried in the earth millions of years ago 2. Limited and will run out 3. The burning of fossil fuels releases air pollutants and greenhouse gasses that contribute to global warming

Question 26

What is solar energy

Answer 26

1. The use of solar panels to harness solar energy and trap light energy and convert it into electrical energy 2. Can generate solar energy without the releasing of pollutants and greenhouses. It requires sufficient care to reduce the amount of toxic waste generated.

Question 27

What is Hydroelectric energy

Answer 27

1. Energy generated from turbines that is powered by moving water 2. The reservoir behind the dam stores gravitational potential energy 3. As it flows down the passageway, the GPE is converted to KE 4. The Ke of the moving water is transferred to the blades that turn 5. The Kinetic energy of the turning blades is converted to Electrical Energy in the generator 6. Produces less greenhouses gasses but it can cause floods and force animals and humans to reclocate

Question 28

What is wind energy

Answer 28

1. The energy that is generated from the wind turbines that spin in the wind 2. The KE from the wind is transferred to the blades of the wind turbine causing it to rotate. 3. A generator connected to the turbines spin and then convert KE into EE 4. It requires the mass clearing of land and destruction of habitats. It can kill birds that collide and cause noise pollution

Question 29

What is Geothermal energy

Answer 29

1. The generating of electrical energy through using heat deep in the earth to generate steam. This turns the turbines and generates EE 2. Cool water is pumped into the hot rocks underground which is heated and turned into steam 3. Hot water and steam is pumped to the surface where steam powers the turbine and produces EE. 4. Requires mass-clearing of land and destroys habitats. As well as the release harmful gasses into the environment

Question 30

What are Biofuels

Answer 30

1. Biofuels are the remains of animal waste and plant materials that are inedible 2. They are used to power Motor vehicles and the carbon dioxide that is produced is re-absorbed by the plants in photosynthesis. 3. It releases carbon dioxide but helps balance the carbon dioxide released when burnt through recycling and reducing wastage

Question 31

What is Nuclear energy

Answer 31

1. Energy harnessed from the nucleus of an atom and converted into EE 2. They use the heat produced when a heavy atom splits to boil water into steam 3. The steam then helps power the turbines and produce EE 4. Nuclear is a clean source of energy and requires less space