Question

A penny falls 380 meters. If dropped from rest, ignoring any air resistance, what is the velocity at which the penny hits the ground? Show your work.

Answer 1

Answer:

Vf = 86.34 [m/s]

Explanation:

To solve this problem we must use the following equation of kinematics.

$v_{f} ^{2} =v_{o} ^{2} +2*g*y$

where:

Vf = final velocity [m/s]

Vo = initial velocity = 0 (falls from the rest)

g = gravity acceleration = 9.81 [m/s²]

y = distance = 380 [m]

Vf² = 0 + (2*9.81*380)

Vf = 86.34 [m/s]

Note: The pisitive sign in the equation above means that the movement goes in the same direction of the gravity acceleration, therefore the velocity is increasing when the penny falls.