Unit 1 - Basic concepts Flashcards
Name 4 SI base units & 1 supplementary unit
Metre
Second
Kelvin
Kilogram
Radian
Equation for velocity?
Change
in displacement/time
Equation for acceleration?
Change in velocity/time
What 2 effects do forces have on objects?
Change in position
Deformation
What can you use to measure a force?
Spring balance
Newton’s 3rd law?
To every action there is an equal and opposite reaction
Define:
- Mass
- Weight
- Density
Mass - quantity of matter in a body
Weight - force of gravity on a body
Density - mass per unit volume of a material
What is gravity?
Acceleration due to gravitational attraction between 2 bodies
W = m x G
Centre of mass & gravity?
CoM - the point where all the mass of an object can be assumed to act
A body in a gravitational field will also have a centre of gravity
What is pressure?
P = F/A (Pa)
What is a moment?
The moment of a force is the tendency of that force to produce a rotation about an axis (also called torque)
Equation for moments?
M = Fd
What is rotational equilibrium?
When all the external moments about a body are equal the body with be at rest
How do you calculate mechanical advantage?
effort arm/resistance arm
If >1 lever is at a mechanical advantage
Describe a 1st class lever
Fulcrum located between effort & resistance
Can work at mechanical advantage or disadvantage
