I drop a penny from the top of the tower at the front of billy jones high school and it takes 30 seconds to hit the ground calculate the velocity in m/s after 25 seconds of free fall

Respuesta :

Answer:

The velocity of the penny at 25th second is, v = 245 m/s

Explanation:

Given,

The time taken by the penny to hit the ground is, t = 30 s

The initial velocity of the penny, u = 0 m/s

The velocity of the penny at 25th second, v = ?

Using the II equation of motion, the displacement is given by the formula

                              S = ut + ½ gt²

                                     = 0 + ½ x 9.8 ( 25²)

                                      = 3062.5 m

Using the III equations of motion

                                v² = u² + 2gs

Substituting the given values,

                                v² = 0 + 2 x 9.8 x 3062.5

                                     = 60025

                                v = 245 m/s

Hence, the velocity of the penny at 25th second is, v = 245 m/s