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
<em> S = ut + ½ gt²</em>
= 0 + ½ x 9.8 ( 25²)
= 3062.5 m
Using the III equations of motion
<em>v² = u² + 2gs</em>
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