The discussion revolves around determining the pitching speed of a baseball thrown horizontally from a height of 4.0 m, landing 25 m away. The problem involves concepts from kinematics, particularly the motion of projectiles.
Some participants have offered guidance on using kinematic equations to analyze the vertical motion and calculate the time of flight. There is ongoing exploration of the correct interpretation of the distance in relation to the problem's geometry, with some participants expressing uncertainty about the setup.
There is mention of ignoring air resistance, which could affect the accuracy of the calculated pitching speed. Additionally, participants are questioning whether the distance of 25 m should be considered as the hypotenuse or the adjacent side in a triangle formed by the motion.
Spinnor said:See towards the bottom of,
http://ngsir.netfirms.com/englishhtm/ThrowABall.htm
Set h = 4, R = 25 , and θ = 0
sjb-2812 said:Are you sure R should be 25 here?
Spinnor said:I'm never sure, 8^)
What do you think it should be?
HallsofIvy said:Your "kinematic equations" refer to the vertical motion only. You say the ball is thrown horizontally so the initial vertical component is 0. The height of the ball, at time t, is y= (1/2)(9.81)t^2+ 4. Set that equal to 0 (the ball hits the ground) and solve for t to find when the ball hits the ground.
Taking "v" as the horizontal component of velocity, the distance the ball traveled, in time t, is given by x= vt. Put x= 25, t equal to the time you solved for above, and solve for v.
That, of course, is ignoring air resistance- which is fairly large for a baseball.