This document defines key concepts related to motion, including speed, velocity, acceleration, force, friction, gravity, and mass. It explains that speed is distance divided by time, velocity includes both speed and direction, and acceleration is the rate of change of velocity. Forces such as gravity and friction can cause or oppose motion depending on whether they are balanced or unbalanced. The law of universal gravitation describes how gravitational force is related to mass and distance. Formulas for calculating speed, distance, and time are also provided.

1. Matter in Motion
• Motion – object changes position over
time relative to a reference point
• Speed – distance divided by time (units
determined by problem (m/s, km/hr)
• Average speed = total distance/total
time
• Velocity – speed of an object with a
direction: 90 km/hr southwest
• Acceleration – the rate at which velocity
changes (either direction or speed)

2. • Force – a push or pull (unit are newton N)
– Force applied does not mean motion will
occur
• Net force – combination of all forces
acting on an object
• Force in the same direction is always
added, force in opposite directions is
always subtracted

3. Add or Subtract force to
determine movement
Same Direction = ADD Opposite Direction = Subtract

4. • Net force that equals 0 is balanced (and
no motion will take place) otherwise the
net force is unbalanced and there will be
motion

5. • Friction – force that opposes motion
between objects that touch
• Static – not moving
• Gravity – force of attraction between two
objects due to their mass

6. • Law of universal gravitation –
relationship between gravitational force,
mass and distance (Newton’s 3 laws of
motion)
• Gravitational force increase as mass
increases and gravitational force
decreases when distance increases
• Mass – amount of matter in an object
(units kg)
• Weight – measure of the force of gravity
on an object due to mass, changes with
location to source of gravity

7. • Weight units are N (100 g = 1 N) NOT POUNDS
• Objects have weight only if there is a source of
gravity present, since all matter has mass, all
objects will experience the force of gravity
depending on the mass of the object and the
distance from the source of gravity

8. Formulas: must have an (=)
equal sign
– s =d / t (speed = distance divided by time)
– d=s x t (distance = speed x time)
– t=d / s (time = distance divided by speed)
– All symbols are lower case
• Remember: units for answer are in the
problem