Welcome to Physics Problems Q&A, where you can ask questions and receive answers from other members of the community.

Stuck on a Problem About Vertical Displacement

1 vote
91 views

I am not sure how to approach the following question:

A baseball is thrown down a hill. This baseball has on-board sensors that can measure its velocities in both the x- and y- directions. The data show that the ball took off with an initial velocity in the y-direction of 4.0 m/s and had a final velocity in the y-direction of -5.8 m/s . How much lower was the ball when it landed compared to where it started?

I figured out the hang time (1.0 s) based on the V(fy) = v(iy) + at formula. However, how do I get the magnitude of displacement from this? I have the equation for x(max) with the sin and cos -- not going to type it here because I'm not sure how to do thetas and such...in any case, how do I find angle theta based on this information so I can solve the equation?

asked Aug 22, 2017 in Physics Problems by tyger2020 (120 points)
edited Sep 12, 2018 by sammy gerbil
Please upvote my answer if you are happy with it. Otherwise, please post a comment.

1 Answer

1 vote

This problem can be solved without considering horizontal (x) motion at all, because vertical (y) motion and horizontal (x) motion are independent.

The vertical velocity at launch is $4m/s$ upwards. When the baseball passes the thrower on its way down its velocity is then $u=4m/s$ downwards. When it lands the baseball's velocity is $v=5.8m/s$ downwards. The vertical distance $s$ of the landing position below the launch position can be found from
$v^2=u^2+2as$.

answered Aug 23, 2017 by sammy gerbil (27,948 points)
...