Applications of Forces and Transfers of Energy Flashcards
INTERACTIONS
What are the effects of forces?
1) Decrease the speed
2) Move a stationary object
3) Change the direction of a moving object
4) Stop a moving object
5) Change the shape of an object
Define a force.
A force is a push or pull that one object exerts on another.
What are the types of forces?
1) Normal Contact Force
2) Weight
3) Friction
4) Air resistance
5) Elatic force
6) Magntic Force
What is a normal contact force?
A pus exerted by a surface on an object pressing on it. This push is always perpendicular to the surface.
What is weight?
It is the gravitational force exerted by Earth on an object.
What is Friction?
A force that opposes or tends to oppose motion. This only exists between 2 objects.
What is Air resistance?
A force that is found in fluids such as oil or air.
What is elastic force?
The pull exerted by a stretched string, spring or rope on an object that is attached to it.
What is a magnetic force?
The push or pull between magnets or magnets on magnetic materials.
What are the 2 types of forces?
They are Contact forces and Non-contact forces.
What are Contact Forces?
Forces acting between 2 objects that are in physical contact with each other are called contact forces.
What are Non-contact Forces?
Non-contact forces are forces between 2 objects that are not in physical ontat wth each other.
Explain on how friction works while walking?
Shoes are designed with treads whih result in the rough soles of our shoes. When we walk, the rough soles of our shoes or feet rub against the ground. Friction between our feet and ground pushes our body forward. On wet ground, the threads are able to channel water out efficiently from under the sandals and increase friction between the shoes and. ground.
Explain how friction works when writing.
When we write with a pencil, the pencil’s tip rub against the rough surface of the paper. Friction transfers carbon lead onto the paper and also allows us to grip the pencil.
How does friction while lighting a matchstick.
Matchsticks are ignited by friction between moving objects. The head of the matchstick rubs against the rough sides of the matchstick box, causing heat. This enables the head to catch fire.
Eplain how friction works during parachuting.
The parachute is a large piece of nylon that produces a large frictional force with air. This reduces the speed of the parachutist’s fall.
What are the negative effects of frictional force?
1) Causing moving objects to slow down and come to a stop.
2) Causes things to heat up and wear out
3) Wastes energy
How to reduce friction?
1) Streamlined shapes to reduce water resistance
2) A cushion of air to reduce friction between one’s base and ground.
3) Lubricants such a ball bearings, wheels and powder may be used to reduce friction.
What are magnetic materials?
A material that can be attracted by a magnet is called magnetic material. One example is metal.
What are non-magnetic materials?
Non-magnetic materials are materials that cannot be attracted. Some examples are aluminium, plastic, rubber, etc.
What are the applications of magnetic force?
1) Removing magnetic materials from non magnetic materials in waste recycling plants.
2) Make use of magnetic force of repulsion to lift a maglev train above its track when it’s moving.
What is gravitational force?
It is the force of attraction between 2 bodies.
What is mass?
A measure of the amount of matter or substance in a body.
What is the formula to find weight?
Weight = mass x gravitational force
