Forces Flashcards
Force=?
Mass x acceleration
N=?
Kg x meters per second
Scalar ?
Vector?
Scalar- unit (value)
Vector- unit + direction (value)
What is a force vector?
Force is a vector quantity, so the arrow shows how big the force is
What is a free body diagram used for?
To show the relative magnitude (size) and direction of all the forces acting on an object in given situation (they are vector diagrams)
What does the length of the arrow show?
It represents the size of the force and has to be to scale
What does the direction of the arrow show?
Represents the direction the force is acting in
What is drag?
When a solid moves through water or air it has to push particles out of the way which slows you down.
Why is it harder for bigger objects to move through air or water?
Because it has a larger surface area which means it has to push or particles out of the way in order to get through
What causes friction?
Most objects that look smooth (e.g hands) on a microscopic level it is not so when you rub your hands together you get the resistive force of friction
What is the purpose of friction?
Friction always tries to slow moving objects down we say it opposes friction
When does friction take place?
When two touching objects or surfaces move past each other. Friction also occurs when things move through air this is called air resistance or drag
There is a maximum value for the frictional force which depends on:?
The force pushing the two surfaces together
The state of the surfaces in contact
Why is friction good?
Because we wouldn’t be able to stand, walk, run and hold things
Why is friction bad?
If you want to move a heavy object it’s hard to move it
It causes heat which is not always good
When is deformation?
The object changes shape due to the force acting upon it
What is tension?
Force extending or pulling apart
What is compression?
Force squashing or pushing together which changes the shape of an object
How do u calculate a moment?
Moment= force x distance from pivot
N/m N M
What is a lever?
A long bar that pivots and is uses forces to move an object
What is one of the laws of gravity?
Gravity is greater towards the bottom
Why do small objects sink?
If the area is too small there will not be enough upthrust to balance the weight and it will sink
