P3.2 Flashcards
Why are liquids used in hydraulics?
~ They’re virtually incompressible (pressure is the same throughout)
~ They flow
What does the process of using hydraulics involve?
Moving things using liquids to transfer forces
What is pressure measured in?
Pascals (Pa)
1Pa = 1N per m2
What is the centripetal force due to?
~ Gravity
~ Friction
~ Tension
What would happen if there was no centripetal force on a roundabout?
The person would fly off in a straight line
Where does the centripetal force act?
Towards the centre
Where is the centre of mass?
The point that the mass appears to act from
What are 2 ways to keep something more balanced?
~ Wider base
~ Lower centre of mass
When is something unbalanced?
When the line of action of weight is outside of the base
What causes the centripetal force needed to make an object move in a circle increase?
~ An increase in mass
~ An increase in speed
~ A decrease in size of circle
How does increasing the length of the pendulum affect the period?
The longer the pendulum, the larger the period
What is the resultant force on an object moving in a circle?
The centripetal force, which causes the acceleration
What is a plumb line?
A piece of string with a weight attached
What is the method for finding the centre of mass of an irregular object?
~ Use a drawing pin to hold plumb line freely over object
~ Pencil line is drawn where the string falls
~ These 2 steps are repeated for another 2 positions on the object
~ The C.o.M is where the 3 pencil markings cross
What is the period of a pendulum?
The time taken for the pendulum to swing to the other side and back again
