p3. forces Flashcards
what are scalar quantities?
only includes magnitude ( size )
what are vector quantities?
includes both magnitude and direction
how are vector quantities represented?
- vector quantity = arrow
- length or arrow = magnitude
- direction of arrow = direction of vector
examples of scalar : vector quantities
- distance : displacement
- speed : velocity
- mass : weight
what are contact forces? give examples
objects that are physically touching
- eg. friction,air resistance,tension
what are non-contact forces? give examples
objects that are physically separated
- eg. gravitational force,electrostatic force,magnetic force
what is work done?
energy transferred ( word done = force x distance )
forces involved in stretching
- weight of mass
- reaction of force ( pulling )
forces involved in bending
- weight of mass
- reaction of force ( compression )
forces involved in compressing
- weight of mass
- reaction of force
why is more than one force applied when stretching,bending and compressing an object?
if we only had one force,we would only be moving the elastic object
what is elastic deformation?
change of shape due to reaction of applied stress
what is inelastic deformation?
material is deformed so much it cannot return to its original shape
RP : the relationship between force and extension for a spring
- secure clamp stand to bench using g-clamp or a large mass
- use bosses to attach two clamps to clamp stand
- attach spring to top of the clamp and ruler to bottom of the clamp
- adjust ruler so it’s vertical, and zero level with the top of the spring
- measure and record unloaded length of spring
- hang a 100g mass carrier from spring - measure and record new length of the spring
- add 100g mass carrier from spring - measure and record new length of the spring
- repeat steps 1-7 until 1000g
