Mass is the amount of matter in an object and does not change, while weight is a measure of gravitational force. Gravity is an attractive force between objects due to their masses, causing all objects on Earth to accelerate at 9.8 m/s^2 toward the ground. If a rock was dropped from a cliff and took 3 seconds to hit the ground, using the gravity acceleration of 9.8 m/s^2 and the equation of motion, its velocity would be calculated as 29.4 m/s.

1. FORCE
Mass: the amount of matter in an
object, its value does not change.
Weight: a measure of the gravitational
force exerted on an object.

2. Gravity
Gravity: a force of attraction between objects
that is due to their masses.
All objects accelerate to the Earth at a speed
of 9.8 m/s2 (meters per second)2
v=g x t (v=velocity, g=gravity(9.8), t=time)

3. If you dropped a rock from a cliff and it
took 3 seconds to hit the ground. How
fast would that rock travel? (gravity is
9.8)
V=g x t
V=9.8 x 3
V=29.4