Question

Vi = 8 ft/s 3 ft The girl throws the ball with a horizontal velocity of v, = 8 ft/s. If the coefficient of restitution between the ball and the ground is e = 0.8. determine the velocity of the ball just after it rebounds from the ground and the maximum height to which the ball rises after the first bounce.

Answer 1

we calculate the velocity of the ball as follows: The kinematic equation is given as follows V-42- 2as v > a final velocity a vy u » initial velocity =o a - acceleration due to gravity = 3202 ift/s² s horizontal displacement = -31t/s V²4²=zas Vy-00? = 2(-32-2 ft/93) (~3 445) 70 Vy? = 13.90ft/s The co-efficient of resituation is given by e = (ve) - (VA) (VA) a vý Ne = wye these values substitute in equation ③ V = 13.90 ft/s y these to e=ong then equo becomes The 0.8 vyro 0-(-13. 9oft/s) Vyna = 11.12.ftls velocity is given as follows. Vo = J (8 m/s)²+(11.12mis)? 13.6 m/s the velocity of the ball is 13.6 m/s]

(b) Maximum height as follows substitute ofry Nzo u= 11.12 ft ls a = -32.2 ftis? h = si in equation w²_uz_zal =(0)²-(11.1244/8) 2 = 2/-3202 ff182) (b) h = loaft i. Tmaximum height is 1.9 ftil