Forces and Speed Flashcards
What is a force?
A push or a pull.
Friction
The force between two surfaces sliding over one another, that causes them to heat up and wear.
Weight
The force that pulls objects towards the centre of the Earth.
Air resistance/drag
A force acting against any object that is moving through the Earth’s atmosphere.
Lift
A force pushing upwards on an object flying through the air.
Upthrust
A force pushing upwards on an object moving through a liquid
Thrust
A push caused by an engine
What is one Newton roughly equal to in grams?
100g
When will an object float?
When it is less dense than the liquid it is placed in.
What is the unit for density?
g/cm^3
Upthrust =
weight in air minus weight in water
Density=
mass /volume
What does weight measure?
The effect gravity is having on an object
What is weight measured in and what do you measure it with?
Newtons, a newton meter.
What does mass measure?
How much of something there is
What is mass measured in and how is it measured?
Kilograms, a mass pan balance
Weight=
mass*10= the attraction of earth= 10N/Kg
What is the Archimedes Principle?
The volume of water displaced is equal to the volume of the object.
What is the Plimsoll Line?
A mark on a ship’s hull which indicates the maximum depth to which the vessel may be safely loaded.
What reduces friction?
Lubrication or streamlining
What are the characteristics of a streamlined shape?
A rounded front; a slowly tapering tail; and a smooth shape with no projections
Volume=
mass/density
Mass=
Density*volume
Distance=
Speed*time
Time=
Distance/speed
Speed=
Distance/time
Independent variable/Input variable
what changes
Dependent Variable/Outcome variable
what we measure
Control variable
what we keep constant
