As a kid I threw a tennis ball directly across the street, just as a car was com

Question

As a kid I threw a tennis ball directly across the street, just as a car was coming. I threw poorly, and it hit the car right on the windshield. Treat the car as a vertical plane of glass coming out ofthe page at 8 m/s. I threw the ball with v0= 12 m/s at an angle of 50 degrees up from horizontal, releasing the ball 1 meter above ground, when the car was 14 m away. a) find the x-y coordinates where the ball hits the windshield. b) what is the magnitude of v and v vector of the ball w.r.t. the windshield upon impact?

Explanation / Answer

for ball vox = 12*cos50 = 7.7 m/s

voy = 12*sin50 = 9.12 m/s

along horizantal

for x1 = vox*T

for car x2 = v*T

x1 + x2 = (vox+v)*T

T = 14/(7.71+8) = 0.89 s

x1 = 7.71*0.89 = 6.8619 m

Y-yo = Voy*T - 0.5*g*T^2

Y-1 = (9.19*0.89)-(4.9*0.89*0.89)

y = 5.3 m

x , y = 6.86 , 5.3

vy = voy + gT = 9.19 - (9.8*0.89) = 0.468 m/s

vx = vox = 7.71 = 7.72 m/s

V = 7.71 i + 0.468 j

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.