Question

a student throws a heavy ball downward off the top of a building with a speed of 14m/s. the ball reaches a speed of 47m/s just before striking the ground. assume the speed changes steadily.
determine all unknowns.
$|v_o|$ = 14 m/s
$|v|$ = 0 m/s
$|v_f|$ = 47 m/s

Explanation:

Step1: Identify given values

Initial speed $|v_o| = 14$ m/s, final speed $|v_f| = 47$ m/s, average speed formula is $\frac{|v_o| + |v_f|}{2}$

Step2: Calculate average speed

Substitute values into the formula.
$\frac{14 + 47}{2} = \frac{61}{2} = 30.5$ m/s

Answer:

The unknown average speed $|V| = 30.5$ m/s