Formulas
Force 2
A=F/M
Newton's 1st law
ForceNet=0
When are forces balanced?
When there is no change in motion (no motion at all or constant velocity and acceleration =0)
static
keeps things in place, why we can walk.
KE
Kinetic energy is the energy an object has due to its motion.
Example 1 You serve a volley ball with a mass of 2.1kg. The ball leaves your hand at 30m/s. The ball has _______ Calculate It
9450 Joules or kinetic
Newtons 2nd law
Force=mass times acceleration
Friction is the contact force between two solids, liquids, or gases that slide past one another. Friction always resists the motion of objects.
sliding
between 2 surfaces rubbing together – bike brakes, you on a slide
GPE
Potential energy is the energy an object has due to its position or chemical composition.
Kinetic Energy
1/2mass times velocity2
Newtons Third Law
every action has an equal and opposite reaction
Gravity is a force that causes matter to be attracted to other matter. Gravity is a relatively weak force compared with other forces, such as electricity and magnetism. The larger the mass of an object, the greater its gravitational pull on another object.
Friction
is a force that opposes motion between two surfaces that are in contact.
Normal reaction force:
the force of gravity on that object when pulling an object across the table (weight x force of gravity, which is always 9.8m/s 2 )
Potential Energy
Mass times Gravity times Height
Newtons first law definition
an object in motion will remain in motion (or an object at rest will remain at rest) until acted on by an outside or unbalanced force.
What causes an object to accelerate
An object will accelerate when it is acted on by an unbalanced force. Heavier objects will accelerate less quickly than lighter objects that experience the same force according to the equation: Force=mass times acceleration (F=maF=ma).
rolling
the least amount of friction occurs, only between the part of the wheel touching the ground and the ground
Coefficient of Friction
a number that describes the degree of mechanical and molecular interaction between two surfaces. High coefficient of friction (close to 1) = lots of friction, low coefficient of friction = low friction. How much friction is between 2 surfaces.
Force
mass times acceleration
Newtons second law definition
an object will accelerate in the direction of a net force F=ma or a=F/m (acceleration depends on the object’s mass and the net force acting on it)
Some forces are contact forces, and some forces can act from a distance. Contact forces are forces that occur when two masses are directly touching, such as the force of friction. Forces that can act from a distance are the electrical force, magnetic force, and gravitational force.
fluid
acts on the front surface of an object moving in a fluid, you in a pool, includes air resistance – kind of a fluid friction because air is a fluid (happens on the front surface of a moving object and in free fall)
Law of Conservation of energy
The law of conservation of energy states that energy cannot be created or destroyed. Kinetic energy can be converted into potential energy, and potential energy can be converted into kinetic energy, but the total amount of energy following the conversion equals the total amount of energy prior to the conversion.