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

Standing on the ground, you throw a baseball straight upward, releasing the ball at a height of 2.00 meters. The ball travels straight up and then falls(ignoring air resistance). If the ball was in the air for a total of 3.92s, find the maximum height the ball reaches and the speed at which it was thrown.

2. Relevant equations

Vf=Vi+at

(Vf^2)-(Vi^2)=2ax

x=(Vi*t)+(1/2)(a)(t^2)

3. The attempt at a solution

I divided my diagram into 3 velocities:

velocity initial (Vo):when the ball was released at 2.00 meters

velocity 2 (V2): velocity at the top of "bell" which is zero

and the velocity once it hit the ground (Vf)

Vi=? V2=0 m/s Vf=? i assume Vf is not important

I am treating time as a net total (3.92) and therefore tnet=3.92=t1+t2

t1: being the time it take for the ball to reach v2

t2: being the time it takes for the ball to go from v2(top of the bell with 0m/s) to the ground

*I treated x the same. Xnet=?=x1+x2

xi:the distance the projectile traveled until velocity became zero. I am assuming x1=2+?

x2: the distance the projectile traveled before reaching x=0 meters

I played around so much with the equations (substituting equations into each other) that I kept getting 2*G as the acceleration. I know thats not right because the ball was thrown upwards and therefore the velocity must be positive.

The answer ended up being:

the ball reached 19.8m high

and 18.7 m/s as the initial velocity.

I've never had a problem like this that hasn't included an initial velocity.

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: A ball is thrown upwards . .

**Physics Forums | Science Articles, Homework Help, Discussion**