forces 2 Flashcards
(16 cards)
what is the centre of mass?
a single point where the weight can be considered to act
what is the method for lines of equibrium? (5)
hang card from thread, suspend card and attach plumb line, draw a line along plumb line, repeat from different point- centre of mass is where the lines cross.
why will shapes topple?
the line of action due to the centre of mass lies outside of the base of the object
how can an object be changed to be more stable? (2)
more weight on the sides rather than the middle, centre of mass moves lower down
how can an object be changed to be more stable? (2)
more weight on the sides rather than the middle, centre of mass moves lower down
what direction do gears move in?
wheels move in opposite directions if put next to each other- smaller wheel moves faster
what is the other name for the turning effect of a force?
moment
how can the turning effect of a force be increased? (2)
high input force, increase distance to the pivot
why do tyres in a tractor have a large area?
so that the weight of the tractor is spread over a large area- reduced amount of pressure
high pressure of force:
force concentrated over small area
low pressure of force:
force spread over large area
why is there pressure in a fluid?
particles in fluid move and collide with any surface that is in contact with the fluid- each particle exerts a small force on the surface it collides with
why is pressure greatest at the bottom of a liquid?
there is a greater weight of liquid at the bottom
why would the pressure of a submarine be greatest underneath
difference in pressure causes an upthrust
why would a tractor exert on the ground?
so they is doesn’t sink into the muddy ground
why does an object on earth experience a pressure from the earths atmosphere?
the weight of the atmosphere pushes down on the earth and the air particles collide on the surface to create pressure
