science 9 4th qt

natural

the downward movement of the object

violent

the upward movement of the object

aristotle

according to him, objects move only when pushed or pulled by something else, so moving objects should quickly come to rest when left to themselves

galileo

however, he discovered that the reason objects usually come to rest is because the force of friction slows down their motion

free fall

• an object falling under the sole influence of gravity

• any object being acted upon only by gravity is said to be in a state of free fall

• do not encounter air resistance

acceleration

• rate of change in velocity in time

• vector quantity having both magnitude and direction

• 9.8m/s²

uniform

• acceleration of a body throughout the motion

• can be observed in either vertical or horizontal dimension

projectile

• form of motion where an object moves in a curved path

• object is thrown or projected and exhibits

trajectory

the arc/curve like motion path undergone by a projectile

horizontal launched

• x component

• neglect air resistance

• there is constant horizontal velocity

vertical launched

• y component

• gravity: acting upon in this motion

velocity

rate of change its position with respect to a frame of reference

height

highest vertical position along its trajectory

angle

figure formed by two rays meeting at a common end point and measured in degrees, using a protactor

linear momentum

the product of the object’s mass and it’s velocity

work

the product of force acting on object and that object’s resulting distance or displacement

joule

unit of work is newton meter so?

energy

the ability or capacity to do work, potential and kinetic

kinetic energy

• the energy ann object has due to motion

• it depends on the object’s mass and velocity

gravitational and elastic

2 types of potential energy

gravitational potential energy

energy stored in an object because of where it is placed. it is found in objects some height off the ground

elastic potential energy

energy that is stored by the forces within a distorted elastic object, it can be found in rubber bands and springs

mechanical energy

sum of the kinetic and the potential

heat

the energy transferred from one object to another due to their temperature difference

thermodynamics

a branch of physics that deals with the physical laws that relate heat and mechanical work

james prescott joule

determined the amount of mechanical work needed to produce a given amount of heat

efficiency

the percentage of work put into a machine by the user that becomes work done by the machine