(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A boy kicks a ball into the air. It takes 4.3 seconds to land 41.1 meters from his position to the right. What is the launch velocity and launch angle of the ball? Ignore air resistance.

Δx = 41.1 m

t = 4.3 s

a = -9.8 m/s^{2}

2. Relevant equations

d_{x}= v_{x}t

v_{fy}= v_{0y}+ at

3. The attempt at a solution

d_{x}= v_{x}t

d_{x}/ t = v_{x}

41.1 m / 4.3 s = v_{x}= 9.56 m/s

v_{fy}= v_{0y}+ at

0 = v_{0y}+ (-9.8 m/s^{2}* 4.3 s)

0 = v_{0y}- 42.1 m/s

v_{0y}= 42.1 m/s

launch velocity = (9.56 m/s)^{2}+ (42.1 m/s)^{2}= v_{i}^{2}

v_{i}= 43.2 m/s

launch angle = v_{xi}= v_{i}cosθ

9.56 m/s = 43.2 m/s * cosθ

θ = 77.2°

Can anyone please look through my work to see if I have done it correctly? I'm getting conflicting answers from wolframalpha.

Thanks!

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