physical science semester 1 final review

freshman year

what is it called if an object has a net force of zero

balanced forces

how does gravity change as two objects move farther apart

it decreases

according to newtons first law what does a moving object do

continue moving at the same velocity unless a force acts on it

what measures an objects tendency to resist change in motion

inertia

what is the combination of all the forces acting on an object

net force

what is a force

a push or pull

which direction is centripetal force in

toward the center of a circle

what is weight

the gravitational force exerted on an object

why do astronauts seem weightless in orbit

the spacecraft is in freefall

what law relates the net force on an object to it mass and acceleration

newtons second law

what is the distance between an object and the reference point

position

what is the equation for momentum

p = mv

earth’s blank causes projectiles to follow a curved path

gravity

how do you find average speed

dividing total distance traveled by the time

what is the instantaneous speed

the speed of an object at any given time

the direction and speed of an object is described by

the velocity

if an object has a constant velocity what is the acceleration

the acceleration is zero

a change in velocity means

a change in speed, direction, or both

when does the kinetic energy of something change

when the objects speed changes

one food calorie is equal to

4000 Joules

what is work

force applied over a distance

when is work done

while you are applying a force on an object

what is a machine

a device that changes the force or increases the motion of work

what is a simple machine

a machine that does work with only one movement of the machine