Question

What is the speed of an object after falling (from rest) a distance of 9.80 meters near the surface of the Earth? Assume air

resistance is negligible,
1 pt for diagram or listed variables
1 pt for correct equation
1 pt for correct substitutions
1 pt for correct answer with units

Answer 1

Hi there!

We can use the kinematic equation:

`v_f^2 = v_i^2 + 2ad`

vf = Final velocity (? m/s)

vi = initial velocity (0 m/s, dropped from rest)

a = acceleration (due to gravity, 9.8 m/s²)

d = distance (9.8 m)

Simplify the equation to solve for vf:

`v_f^2 = 0 + 2ad\\\\v_f = √(2ad)`

Substitute in the given values:

`v_f = √(2(9.8)(9.8)) = \boxed{13.86 m/s}`