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

A ball is thrown with a velocity of 20.0 m/s [30 degrees] and travels for 3.0 s before it strikes the ground. Find the

a) height from which it was thrown.

b) the maximum height of the ball.

2. Relevant equations

a) d_{x}= v_{x}• t ... I don't even know what to do for part A.

b) v^{2}_{f}= v^{2}_{i}+ 2ad

3. The attempt at a solution

a) I absolutely have no clue what to do for part A.

I first thought to use triangles and tried to find the distance the ball travelled using the velocity I found, but it doesn't even work.

b) I realized that at the maximum height, the velocity of the object will me 0 m/s, so I tried to find the distance from that point to the ground to find the maximum height.

I found the initial velocity to be 10 m/s using SOH and i used the above formula.

v_{iy}: 10 m/s

v_{fy}: 0 m/s

g(a): -9.81 m/s^{2}

0^{2}m/s= 10^{2}m/s + 2 • -9.81 m/s^{2}• d

0 m/s = 100 m/s + -19.62 m/s^{2}• d

-100 m/s = -19.62 m/s^{2}• d

d = 5.1 m

It's not the right answer, so I don't know where I went wrong.

I don't know if any of what I did makes sense, I'm so lost in projectile motion.

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# Homework Help: Physics - Projectile Motion

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