physics Flashcards
Scalar Quantities
a quantity that has size but not direction (distance not displacement)
Vector Quantities
a quantity that has size and direction (distance and displacement)
Distance (d)
how far an object travels in total (scalar quantity)
D = st
distance = speed x time
Displacement (s)
the straight-line distance between the start and finish points with a physics chemistry direction (vector quantity)
S = final velocity – initial velocity
speed
scalar quantity
ms-1
symbol: Vav
Vav= distance/time
velocity
vector quality (+ direction)
ms-1
symbol: Vav
Vav= distance/time
Average velocity
final velocity + initial velocity / 2
acceleration
change in velocity/speed (rate)
object change speed/direction = acceleration
unbalanced forces = acceleration
final velocity - initial velocity / 2
Newtons 1st Law
Known as the law of inertia
Moving objects keep moving. Objects at rest stay at rest. Unless acted upon by an unbalanced force.
Newtons 2nd Law
F=ma
More force means more acceleration. More mass means less acceleration
Newtons 3rd Law
Every action has an equal and opposite reaction
E.g. A big year 12 bumps a small year 7 in a footy game.
Year 7 goes flying (large acceleration)
Year 12 stays still (small acceleration).
State and explain the law of conservation of energy
Energy cannot be created or destroyed, only transferred or transformed.
E.g. When playing pool, the cue ball is shot at a stationary 8 ball. The cue ball has energy. When the cue ball hits the 8 ball, the energy transfers from the cue ball to the 8 ball, sending the 8 ball into motion. The cue ball loses energy because the energy it had has been transferred to the 8 ball, so the cue ball slows down.
