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

"A ball player hits a home run, and the baseball just clears a wall 21.0m high located 130.0m from home plate. The ball is hit at an angle of 35.0degrees to the horizontal, and air reisistance is negligable. Assume the ball is hit at a height of 1.0m above the ground

a. What is the speed of the ball?

b. How much time does it take for the ball to reach the wall?

c. Find the velocity components and the speed of the ball when it reaches the wall."

Variables(this was my attempt at interpreting the question):

Delta y = 20.0m

Delta x = 130.0m

theta = 35degrees

2. Relevant equations

This is where I'm confused. The only equation I could come up with was:

[tex]\Delta y=-\frac{1}{2}g(\Delta t)^2[/tex]

3. The attempt at a solution

The only thing I could do was plug in the numbers(20 for delta y, -9.81 for g),to get [tex]20.0m=-\frac{1}{2}\left(-9.81\frac{m}{s^2}\right)(\Delta t)^2[/tex] and solve for t. I got 2.02s, which is not the right answer for part b, which is 3.81s. I would like to understand how to solve the equation, perferably myself, so if someone could give me guidance, rather than a solution, I would appriciate it.

Thanks,

mike

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# Homework Help: Help with a two-dimensional motion problem

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