Forces, Energy and Power Flashcards
Energy equations
Ew=Fd
Ep=mgh
Ek=1/2mv^2
how to work out horizontal and vertical components of force acting on a box
SOHCAHTOA
Fh=Fcos theta (cos across)
Fv=Fsin theta (sin up)
how to work out components of force down a slope
- component of weight acting down slope = mgsin theta
- component of weight acting normal to the slope = mgcos theta
what happens if the angle increases on a slope
bigger angle –> Fh increases –> acceleration down slope increases
balanced forces
equal in magnitude but opposite in direction
how to work out friction
Fun=Fh-friction
Ek at ground=
Ep at max height (h=v^2/2g)
if a rope or cable is pulled tight…
there will be tension in the rope
if no angle, tension=
Weight
tension depends only on the…
mass it is pulling
what happens to tension as angle increases?
tension increases because the horizontal component increases and the vertical component remains the same
equation to work out tension at angles
cos theta = W/T (z angles)
what is power?
the rate at which energy is transferred
what is work done?
a measure of the energy transferred/converted during a process
friction
the force that opposes the motion of all objects
