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P2 Forces & Motion Part 2 - Coggle Diagram
P2 Forces & Motion Part 2
Measuring speed using light gates
Use the light gate to start and stop a timer when an object passes through.
Divide the distance by the time to find the average speed of the cart between the light gates.
Measure distance between the light gates.
Typical speeds
Walking - 1.5 m/s
Running - 3 m/s
Cycling - 6 m/s
Car - 10-30 m/s
Aeroplane - 200-250 m/s
Sound - 330 m/s
Acceleration in free fall = 10 m/s^2
Circular motion
An object moving in circles has a constant speed and changing velocity as it is constantly changing directions.
For an object to move in a circle there must be a force pulling it towards the centre, this is the centripetal force. There are three types:
Tensile strength
Friction
Gravity
Newton's laws
Newton's First Law
States that any object's motion will not change unless a resultant force is acted upon it.
Newton's Second Law
Net force is directly proportional to acceleration. Acceleration is inversely proportional to intertial mass. F = ma
Inertial mass is a measure of how difficult it is to chage the velocity of an object, defined as force:acceleration.
Newton's Third Law
States that for every action by one object there is an equal and opposite reaction on the other object.
Momentum
Momentum is what keeps an object moving in the same direction and makes it difficult it change it's velocity.
Momentum = mass x velocity
Weight
The force acting on an object due to gravitational attraction.
Weight = mass x gravitational field strength