Card Set Information
What is a moment?
of a force
How are moments calculated?
Moment (Nm) = Force (N) x distance from pivot (m)
What is a pivot?
The point around which something turns
an alternative word for?
What is a
Something that uses moments to make a task require less force (make it easier)
Name some examples of levers
Scissors (especially nail scissors)
What do we know about the anti-clockwise moment and the clock wise moment if an object is not turning?
What are the units for force?
What are the units of distance?
What are the units of moments?
Newton metres (Nm)
What is a pendulum?
An object that swings to and fro
What affects the time that a pendulum takes to make a complete swing?
The length of the pendulum (nothing else!)
What name we give to the time for a pendulum to make a complete swing (back to its starting place)?
What unit is used to measure time?
What unit is used to measure speed?
Metres per second (m/s)
What unit is used to measure acceleration?
Metres per second squared
What is the equation for calculating acceleration?
change in speed / time taken
Name the force that keeps objects moving in a circle
In which direction does centripetal force act?
Towards the centre of the circle
What is the unit of centripetal
things affect the size of the centripetal force needed to keep an object moving in a circle?
Radius of the circle
Speed of the object
Mass of the object
Does increased speed need a larger or smaller centripetal force?
If the radius of the circle increases, what effect does this have on the centripetal force needed?
If the mass of the object increases, what effect does this have on the centripetal force needed?
What provides the centripetal force that keeps the Earth orbiting around the Sun?
What provides the centripetal force that keeps a conker tied to a piece of string moving in a circle
in the string
In which direction does air resistance act?
Opposite to the direction of travel
If the speed of an object increases, how does this affect the air resistance?
Air resistance increases
If forces are balanced what do we know about the speed of an object?
It moves at a constant speed.
(If it was not moving it stays not moving)
What is terminal velocity?
The speed an object moves at when the forces acting on it are balanced.
eg a skydiver falling when her weight and air resistance are equal
Why does opening a parachute increase air resistance?
The parachute has a large surface area
What are the two units of
or Pascals (Pa)
What is the equation to calculate
What are the units for Area ?
a measure of?
How hard to start or stop something moving
things affect the inertia of an object?
When a skydiver is falling, does her
change as her speed changes?
Air resistance (Her weight is constant)