Forces Flashcards
What is a force?
anything that can cause an object to start moving or changing direction
What is the unit of force?
Newtons (N)
What instruments measure force?
Newton meter or a Force sensor
What is friction?
a force that opposes motion between 2 objects in contact.
What are some disadvantages of friction?
- Slows things down
- Wastes energy
- Causes wear e.g. shoes, tires
What are some advantages of friction?
- Allows breaks to be used
- allows you to move
- Slows down hailstones and rain
What does Hooke’s Law state?
the extension of a spiral spring is proportional to the applied force
What is an elastic limit?
the point where a spiral spring will not return to its natural state
What is mass?
the amount of matter in a substance
What is weight?
The measure of the force of gravity on a body
What is mass measured in?
Kilogram (Kg)
What is weight measured in?
Newton (N)
What instrument measures mass?
A mass balance
What instrument measures weight?
A newton meter
What are some differences between mass and weight?
- Mass remains constant everywhere in the universe while weight depends on the amount of gravity in that location.
- Mass: Kg Weight: N
- Mass: mass balance Weight: Newton meter
What is the equation to calculate the weight of an object?
Mass (Kg) X Acceleration due to gravity (m/s²)
What does stationary mean?
Not moving
What does accelerate mean?
Speed up
What does decelerate mean?
Slow down
What is net force?
The total force acting on an object when all forces are added up.
What is a magnet?
A piece of metal that attracts other materials.
What is a magnetic field?
the space around a magnet that exerts force on magnets and magnetic materials.
`What does friction depend on?
The type of surface or the motion between the 2 objects in contact
How can you reduce friction?
⇒Reduce how bumpy the surface is e.g. lubrication, sandpaper.
⇒Ball bearings
⇒Streamlining
