9I - Forces and Motion Flashcards
Speed ( KM / H )=
Distance ( KM) / Time ( H )
Moments ( NM ) =
Force ( N ) x Distance from PIVOT ( M )
Work Done ( J )
Force ( N ) x Distance in direction of FORCE ( M )
The main stores of energy are
Kinetic , Gravitational Potential , Elastic Potential , Chemical and Thermal
Example of Kinetic energy store
Any moving object (car, airplane, e.t.c.)
Example of Gravitational potential store
Any object above the ground (holding a book up)
Example of Elastic Potential energy store
Any object with a rubber band (Slingshot)
Example of chemical energy store
Food, Coal, Batteries
Example of Thermal energy store
A radiator
The main energy transfers are
Heating , Electrical , Radiation and Mechanical
Example of Heating transfer
Friction
Example of electrical transfer
plugging in a socket
Example of radiation transfer
turning on a light
Example of mechanical transfer
steam or fuel in a car
Accelerate
get faster
Upthrust
a force that acts upwards
Friction
-A force that acts between two things touching
-Can be reduced by two smooth surfaces and lubricants
Air resistance
a force that acts to slow down things moving through the air
Water resistance
a force that acts to slow down things moving through the water
Resultant
The difference between the forces in one direction and the opposite direction
Balanced Forces
when all the forces in one direction are exactly the same size as the forces in the opposite direction
Weight
A downwards force caused by gravity
Unbalanced forces
-Can change the speed or direction of movement of an object
-When forces acting in opposite directions aren’t the same length
Drag
- Another name for resistance (Any kind)
- Usually acts to slow down or stop moving objects
Balanced forces affect objects by:
- keeping them stationary
- moving an object with constant speed
Renewable source:
Renewable resources are an energy source that cannot be depleted and are able to supply a continuous source of clean energy. Can it replenish itself in a lifetime?
Non-renewable source:
A non-renewable resource is a natural resource that cannot be readily replaced by natural means at a pace quick enough to keep up with consumption.
Class 1 Lever
Load is on the other side of a pivot
Example of a class 1 lever
Seesaw
Class 2 lever
Load is ‘inside’ the effort
Example of a class 2 lever
Wheelbarrow
Class 3 Lever
Load is ‘outside’ the effort
Example of class 3 lever
Biceps
Moment
A turning force
Work done
energy transferred
Relative Speed
The speed of one object in relation to another
How to find relative speed
-If in same direction, ADD
-If in opposite directions, SUBTRACT
Pulleys
A simple machine that can change the applied force of the work done
Simple Machine
A mechanical device that changes the direction or size of the force in order to make the task easier
How do pulleys work
They change the direction of force, making it much simpler for us to move objects. They increase mechanical advantage.
Energy efficiency
-When the energy is used more than wasted.
-When less energy is used to perform the same task
