Force And Work Flashcards
What is force?
Something that causes an object to accelerate
State the unit of force
Newtons
Name 5 types of force?
Weight, friction, tension, reaction, twisting
What effect does weight have?
Moves objects towards the centre of the earth.
What effect does friction have?
Slows objects moving over each other
What effect does tension have?
Moves objects on pulleys or stops a body falling
What effect does reaction have?
Supports or balances a weight
What effect does twisting have?
Causes rotation
Identify weight as a force
The weight of an object is the force of gravity on it.
Define friction
A force which opposes motion between two objects in contact.
Give two disadvantages of friction
- slows things down.
- Wears away surfaces in contact with each other.
Give two advantages of friction
- Stops or slows things down.
- Allows us to pick up things.
Describe an experiment to investigate friction and the effects of lubricant?
- Attach the Newton-meter to the block on a bench or surface, pull the block.
- Note the reading just as the block is about to move, do this a few times for accuracy.
- place large weights on top of the block. Measure again the force needed to move the block.
- attach sandpaper onto the bottom of the block and repeat
- Remove sandpaper and put some oil on the surface beneath the block, repeat.
Explain stretching forces?
When force is put on them they change shape.
When the force is removed they return to their original shape.
State Hooke’s law
The extension of a spring is directly proportional to the force that is stretching it.
