forces Flashcards
What is a scalar quantity?
Something that can be measured but ONLY has a magnitude (size).
Name 3 examples of scalar quantities.
~Temperature
~Distance
~Mass
What is a vector quantity?
Something that has both magnitude and direction.
Name 3 examples of vector quantities.
~Force
~Velocity
~Momentum
Name 3 examples of contact forces.
~Tension
~Friction
~Air Resistance
Name 3 examples of non-contact forces.
~Magnetic force
~Electrostatic
~Gravitational
What is Gravitational Field Strength measured in?
Newtons per Kilogram (N/KG)
What is the Earth’s Gravitational Field Strength?
9.8N/Kg
What is the equation for weight?
Weight= mass x gravitational field strength
Define work done.
When an energy is transferred from one store to another or when a force causes an object to move.
What is the equation for work done?
Work done(J)= Force(N) x Distance(M)
Define a moment.
The turning effect of a force.
What is the equation for moments?
Moment = force x distance
What is a moment measured in?
Newton-metres
What is a lever?
A simple machine consisting of a pivot, effort and load.
What is a gear?
A wheel with toothed edges that rotates on an axle.
What is pressure?
The force per unit of area and determines the effect of a force on a surface.
What is pressure measured in?
Pascals (Pa).
What is the equation for pressure?
Force normal to a surface divided by area of that surface.
How do you calculate pressure in a liquid?
Height of column x density of the liquid x gravitational field strength
What is atmosphere?
The layer of air around the earth that is thin and becomes less dense as the altitude increases.
What is atmospheric pressure caused by?
Air molecules colliding with a surface.
What is the equation for Hooke’s Law?
Force = spring constant(K) x extension(e).
What is Hooke’s Law?
A measure of stiffness of a spring up to its limit of proportionality.
What is the limit of proportionality?
Point that is beyond Hooke’s Law and makes it untrue.
What is elastic potential energy?
Energy stored in a spring.
What is the equation for elastic potential energy?
0.5 x spring constant x (extension) squared
