The discussion focuses on calculating the initial speed of a baseball hit at a 45-degree angle, covering a horizontal distance of 200 meters. The relevant equations for projectile motion, particularly the SUVAT equations, are emphasized. The key formula derived is u²sin(2θ)/g = R, where u is the initial velocity, θ is the launch angle, g is the acceleration due to gravity (9.8 m/s²), and R is the range (200 m). Participants clarify the importance of separating horizontal and vertical motion to solve for the initial speed effectively.
PREREQUISITESStudents studying physics, educators teaching projectile motion, and anyone interested in understanding the mechanics of sports physics.
Yes, I did this.Brianna I said:Ok, when I was initially taught this I was told to make a chart in both the x and y with what you know and do not know.
The setup would be something like this:
______ X _____ Y
a =
vi =
d =
t =
From there try to solve for maybe t using the y-variables (since you don't have that either) and then plugging in t in an equation that will give you Vix.
I have not gotten any of it done because I have no idea which formula to use. All I know is that on my horizontal I have d = 200 m and a = 0. Then for my vertical I have d = 0 and a = 9.8m/s^2(down). I don't have time and all the formulas I was given deal with time which is why I am confusedgneill said:You need to show what you've done before we can help.
Veronica_Oles said:I have not gotten any of it done because I have no idea which formula to use. All I know is that on my horizontal I have d = 200 m and a = 0. Then for my vertical I have d = 0 and a = 9.8m/s^2(down). I don't have time and all the formulas I was given deal with time which is why I am confused
Yes I know those.haruspex said:For motion under constant acceleration, there are five standard variables (usually known as SUVAT, s for displacement, u for initial speed, v for final speed, a for acceleration, t for time). There are correspondingly five equations. Each equation omits one of the five variables. Are you familiar with these?
Since you do not care about time, pick one that does not involve time.Veronica_Oles said:Yes I know those.
haruspex said:Since you do not care about time, pick one that does not involve time.
The only one I see that doesn't involve time is vf^2 = vi^2 + 2adharuspex said:Since you do not care about time, pick one that does not involve time.
Sorry, I wasn't thinking clearly. You do care about time, but you have to start with the horizontal direction. If it is hit with speed v, how long to reach ythat distance?Veronica_Oles said:The only one I see that doesn't involve time is vf^2 = vi^2 + 2ad
T= 200/ViCos 45 ??!haruspex said:Sorry, I wasn't thinking clearly. You do care about time, but you have to start with the horizontal direction. If it is hit with speed v, how long to reach ythat distance?
Yes.Veronica_Oles said:T= 200/ViCos 45 ??!
What is the initial vertical speed? How long before it lands?Simon Dobbs said:still confusing me
if u is the initial velocity at an angle θ with the horizontalVeronica_Oles said:A baseball player hits a ball 200.0m home run. The ball travels at angle of 45° with the horizontal just after being hit. Determine the initial speed. Assume the ball lands the same height it was hit.