A ball is thrown upward with an initial velocity of 12.1 m/s. How long will it take to reach a velocity of - 24.5 m/s?

Answer;

= 3.73 seconds

Explanation;

Using the equation;

v = u + at

where v is the final velocity, u is the initial velocity and a is the acceleration due to gravity (-g) and t is the time taken.

Therefore;

v = u - gt

Thus;

v = 24.5 m/s, u = 12.1 m/s, a = - g = 9.8 m/s²

-24.5 m/s = 12.1 - 9.8 * t

36.6 = 9.8 t

t = 36.6/9.8

= 3.73 seconds