Gravity & Free Fall



Gravity is Acceleration!

  • Gravity makes things fall down toward the center of the Earth.

  • Falling objects accelerate at about 10 m/s².

  • More precisely, gravity is 9.8 m/s².

  • Everything falls with the same acceleration when air resistance is ignored.

  • Near the surface of the Earth, the acceleration due to gravity is:

g = 10 m/s²

Motion Equations

d = ½at²

vᶠ = vᶦ + at

When something is dropped:

  • Initial velocity: vᶦ = 0

  • Acceleration: a = g

Free Fall Equations

d = ½gt²

vᶠ = gt

Example: Dropping a Rock

If a rock is dropped from a height of 80 m:

Time (s)

Velocity (m/s)

Distance Fallen (m)

0

0

0

1

10

5

2

20

20

3

30

45

4

40

80

The distance is calculated using:

d = ½(10)t²

So, after 4 seconds:

d = ½(10)(4²) = 80 m