Forces Flashcards
Atmospheric pressure
The pressure caused by the weight of the air above a surface.
Centre of gravity
The point in an object where the force of gravity seems to act.
The centre of mass
The point in an object where all the mass of an object seems to act.
Compression
Force squashing or pushing together, which changes the shape of an object.
Contact force
A force that acts when an object is in contact with a surface, air, or water.
Deformation
Changing shape due to a force
Drag force
The force acting on an object moving through air or water that causes it to slow down.
Elastic limit
The point beyond which a spring will not return to its original length when the force is removed.
Equilibrium
State of an object when opposing forces are balanced.
Extension
The difference between the original length of an object and the length when you apply a force.
Fluid
A substance with no fixed shape, a gas or a liquid.
Friction
Force opposing motion which is caused by the interaction of surfaces moving over one another. It is called ‘drag’ if one is a fluid.
Gas pressure
The force exerted by air particles when they collide with a surface.
Hooke’s law
A law that says that if you double the force on an object, the extension will double (directly proportional)
Incompressible
Cannot be compressed (squashed).
Law of moments
An object is in equilibrium if the clockwise moments equal the anticlockwise moments
Linear relationship
When two variables are graphed and show a straight line which goes through the origin, and they can be called proportional.
Liquid pressure
The pressure produced by collisions of particles in a liquid.
Lubrication
A substance that reduces friction between surfaces when they rub together.
Moment
A measure of the ability of a force to rotate an object about a pivot.
Newton
The unit that forces are measured in. (N)
Newton meters
The unit of moment.
newtons per metre squared
The unit of pressure (also Pascals)
Pivot
The point about which a lever or see-saw balances or rotates.
Pressure
The ratio of force to surface area, in N/m2, and how it causes stresses in solids.
Reaction force
The support force provided by a solid surface like a floor.
Streamlined
Shaped to reduce resistance to motion from air or water.
Stress
The effect of a force applied to a solid, found using stress = force/area.
Tension
Force extending or pulling apart.
Upthrust
The upward force that a liquid or gas exerts on a body floating in it produced by the collisions of the particles in the liquid or gas
Water resistance
The force on an object moving through water that causes it to slow down, also known as drag.
