Energy n Forces Flashcards
How do forces in nature affect us
- They cause natural disasters that destroy buildings and roads which result in the loss of lives
- They also help shape our physical environment
Types of forces
- Contact forces: Forces that act when an object is in contact with another
- Non-contact forces: Forces that can act from afar and do not require contact.
What is Frictional force
- It is a contact force
- Force that opposes the motion between two surfaces in contact.
What are the advantages of Friction
- We can walk on the ground without slipping
- We can hold onto objects without dropping them
What are the disadvantages of Friction
- Causes wear and tear
- Cause a waste of energy
What is Gravitational force
- It is a non-contact force
- It is a force that attracts two objects toward each other
- A planet that exerts gravitational force pulls an object toward its centre causing the object to have weight.
Effects of Gravity
- Causes the earth to orbit around the sun
- Causes things to drop to the ground when we let go
What is Magnetic Force
- It is a non-contact force
- It is a force that exerted between a magnet and a magnetic material or another magnet itself
How to phrase attraction/repulsion
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
Application of Magnets in real-world context
- Maglev trains.
- The Maglev train slightly lifts up due to the magnetic force of repulsion.
- 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
Weight Characteristics
- Weight is the amount of gravitational force acting on an object
- Measured in Newtons (N)
- Measuring instrument is Spring balance
- Changes depending on the height you are at
Mass characteristics
- Mass is the amount of matter in an object
- Measured in Grams or Kilograms (g/kg)
- Measured by an electronic balance
- It does not change depending on height you are at
How to measure force
Spring balance and hook the object onto it and see how far the spring extends.
What are the effects of forces
- Forces can move a stationary object
- Forces can stop a moving object
- Forces can change the direction of a moving object
- Forces can change the speed of a moving object
- Forces change the shape and size of an object
- Causes the turning effect
Turning effect
Causes an object to move about a fixed point known as the pivot