The Way you Move Flashcards
What are the laws on?
motion of anything
Define force-
Something which changes the shape or motion of an object
what is force measured in
Newtons
Forces can:
change the speed of an object
change the direction of movement of an object
change the size or shape of an object
Weight
A force that is due to the pull of gravity
Mass of an object=
the amount of matter in it
measured in kilograms
remains the same everywhere
Balanced forces:
A force is needed to start something moving or to change its direction
Forces are also acting on things that are not moving
If something is staying still the forces acting on it must be balances
Newtons first law states
Ever mass stays at rest to moves at a constant speed in a straight line unless a resultant force acts on it
Inertia-
an objects resistance to change in motion depending on its mass
It remains the same on earth and in space as it depends on mass
1st law
when an object is stationary it needs a force to make it move
the bigger the mass the bigger the force needed to make it move
Moving objects also need a force to stop them moving, as their inertia tends to keep them moving in the same direction
Why do you feel pressed back into the seat when a car takes off quickly?
Because your inertia tries to keep you in the same place, it takes some effort to get your body moving at the same speed as the car
Why are you thrown forward when a car stops suddenly?
Because your inertia tries to keep you moving forward and it takes the force from your seatbelt to slow you down
Newtons 2nd law states:
That when an unbalanced force acts upon an object it accelerates in the same direction of the force. The acceleration is directly proportioned to the mass
F=Ma
(Remember Triangle)
Examples newtons 2nd law
weights at the gym
It is easier to throw a lighter object than it is to throw a heavier object
2nd law
if you want to move an object to another place you will have to add a force
the size and the direction of the force are important- this is called a vector quantity
Acceleration
the rate of change of velocity (m/s/s)
an object accelerates/ decelerates only if a force is applied to it
forces control acceleration but not velocity
Depends on the size of the force and how much mass the object has
a large force accelerated a light object very fast, a small force accelerates a massive object slowly
A force is..
an action exerted upon a body in order to change its state of rest or its state of uniform motion in a straight line. Action tends to produce a change in motion.
Newtons third law states :
that for every action their is an equal and opposite reaction
the action force and the reaction force are always equal and opposite
speed
the rate at which a distance is covered
distance
the total length of a journey
formula speed, distance and time
speed= distance/ time
triangle: distance
speed time
Acceleration formula
a= v-u
t
GPE stand for
gravitational potential energy
KE stands for
Kinetic energy
what is gpe
the energy ‘stored’ in an object that is raised against a gravitation on a field
This energy equals all the energy required to get it there
given the right condition formss it will fall + ‘release’ the energy changing it into different
gpe=
mgh
m=mass
g=acceleration due to gravity
h=change in height
what is KE
The energy of a moving object. when an object falls its GPE turns into KE
KE=
1/2mvsquared
m=mass
v=velocity
total energy=
GPE + KE
the acceleration of an object depends on…
the net force on the object and the mass of the object
when the net force is increased the acceleration..
increases
when the net force is decreased the acceleration..
decreases
an object with a larger mass needs a…. to move at the same acceleration as an object with a small mass
stronger force
an object with a larger mass needs a stronger force to move at the same acceleration as an object with a small mass. This is known as -
newtons second law of motion (f=ma)
relationship between distance, speed and time
when an object moves in a straight line at a steady speed, you can calculate its speed if you know how far it travels and how long it takes. Vice versa with distance and time, you can use different variations of the formula to calculate each
GPE turning into KE
min gpe, max ke -> 50% gpe, 50 %ke -> max gpe, min ke -> 50% gpe, 50% ke -> min gpe, max ke
