MATH SOLVE

3 months ago

Q:
# Marsha serves the Volleyball to Rhonda with an upward velocity of 14.5 ft./s. The bar is 4 feet above the ground when she strikes it. How long does Rhonda have to react, before the Volleyball hits the ground? Round your answer to two decimal places.

Accepted Solution

A:

Answer:The taken by Rhonda to react before volleyball hits ground is 2.39 seconds Step-by-step explanation:Given as :The upward velocity of the volleyball = 14.5 ft/sThe height of the ball above ground = 4 feetConsider value of acceleration due to gravity = 9.8 m/sLet the time for Rhonda to react before ball hits ground = t secNow, S = u t + [tex]\frac{1}{2}[/tex] a t²where s = height u = initial velocity , a = acceleration due to gravity , t = time in secSo, 4 = 14.5× t + [tex]\frac{1}{2}[/tex] × 9.8 × t²or, 4 = 14.5 t + 4.9 t²or, 4.9 t² + 14 .5 t - 4 = 0Now, solve for t t = [tex]\frac{-b\pm \sqrt{b^{2}-4\times a\times c}}{2\times a}[/tex]or, t = [tex]\frac{-14.5\pm \sqrt{14.5^{2}-4\times 4.9\times (4)}}{2\times 4.9}[/tex]Or, t = [tex]\frac{-14.5\pm \sqrt{80.5025}}{9.8}[/tex]Or, t = - 2.39 , - 2.76Hence The taken by Rhonda to react before volleyball hits ground is 2.39 seconds . Answer