Motion Flashcards
Speed Distance Time
V=d/t
Rearranged to
t=d/v
D=vt
Average Speed
Average speed = total distance travelled/total time taken
Instantaneous speed
Instantaneous speed = length of card/time taken to break beam
Acceleration
Ms-2
A=v-u/t
Acceleration = final speed - initial speed/time
Rearranged to
T=v-u/a
v=u+at
u=v-at
Speed time graphs
Distance travelled = area a + area b + area c - etc
Acceleration is the gradient of the line
Weight
W = mg
Weight=mass x gravitational field strength
Rearranged to
M=w/g
G=w/m
Newton’s second law
F=ma
Force=mass x acceleration
Balanced and unbalanced forces
To find them take the smaller one away from the larger one
Newton’s first law
When no forced or balanced forces act on an object it remains at rest or continues on at steady speed in a straight line
Newton’s third law
If object a exerts a force on object b then object b exerts an equal but opposite force on object a
Action force and reaction force
Work done
Ew=fd
Word done = force x distance
Measure of the energy transferred during an energy transformation
Work done has the symbol Ew and is measured in joules
If a constant force is applied over a particular distance, a certain amount of energy is required this is called work done
Power
Power is the rate at which energy is transformed during an energy transformation
Power has the symbol p and is measured in watts
P=e/t
Power = energy/time
Gravitational potential energy
Ep=mgh
Gravitational potential energy= mass x gravitational field strength x height
Kinetic Energy
Ek=1/2mv(2)
Kinetic energy = 1/2 x mass x velocity(2)
what is weight
the weight of an object is the force on it due to the earths gravitational pull.
mass remains constant no matter where the object is in the universe but weight depends on the planet
measured in newton’s
what is gravitational field strength
the gravitational field strength (g) is the force exerted per unit of mass of an object.
measured in Nkg-1
what is a force
forces can change the shape, speed and direction of motion of an object
measured in newton’s N
balanced forces
when equal forces act in opposite directions they are called balanced forces
equivalent to no forces
see newton’s first law
unbalanced forces
when unbalanced forces act in an object the object changes speed or direction. the acceleration due to an unbalanced force depended on the mass of the object
calculated using newton’s second law
what is work done
work done is the measure of the energy transferred during an energy transformation
work done has the symbol Ew and is measured in joules J
what is power
power is the rate at which energy is transferred during an energy transformation.
power has the symbol P and is measure in watts W
what is gravitational potential energy
the change in gravitational potential energy or Ep of an object is the work done against gravity (lifting) or by gravity (falling)
gravitational potential energy is measured in joules J
what is kinetic energy
kinetic energy (Ek) is the energy of an object due to motion.
measured in joules J
the kinetic energy increases as the mass and or speed increases
what is the conservation of energy
during any energy transfer the total amount of energy stays the same.
this principle allows numerical problems involving different forms of energy to be solved
