Forces

• Pressure is calculated by force / area
• Pressure is measured as N/m^2
• Pressure is always greatest at the bottom of a liquid and decreases as you move up the liquid.
• The greater the density ,the greater the pressure
• The greater the depth , the greater the pressure
• Density = mass/volume
• The unit for density is g/cm3 or kg/m3
• An object will float on a liquid if it is less dense than the liquid.
• Effort is the force exerted at one end
• Load is the weight of the object that will be lifted
• Moment is the turning forces around a pivot
• Moment = force x distance
• A pulley system can change the direction of the effort, but not the size of the load
• Friction is the resistance to motion when two surfaces are touching