- #1
RoganSarine
- 47
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Now I'm seriously just tired and can't get these, but I don't know why this is wrong at all. This would help if I had a study partner in my physics class (to bounce ideas off of), but no one else in my class is overly strong in the subject.
A batter hits a pitched ball when the center of the ball is 1.22m above the ground. The ball leaves the bat at an angle of 45 degress with the ground. With that launch, the ball should have a horizontal range (returning to the launch level) of 107m
(a) Does the ball clear a 7.32m high fence that is 97,5 n horizontally from the launch point? (b) At the fence, what is the distance between the fence top and the ball center?
y = (tan theta)x - (g(x^2))/(2(vicos45)^2)
R = (2Vi^2/g)(Sin 2 Theta)
107 = (2Vo^2/g) * Sin 2(45)
107 * g = 2Vo^2 * 1
1048.6 / 2 = Vo^2
524.3 = Vo^2
22.89 = vo^2
y = (tan 45)(97.5) - (9.8(97.5)^2) / ((2)(-524.3)(cos45)^2)
y = 97.5 - 177.58
y = -80
The ball clears the fence, so why am I getting -80 for the y coordinate?
Okay, how about this... Let's try using basic kinematics
vix = d/t
t = d/vix
t = 97.5/(22.89cos45)
t = 6.023
d = Viy(t) + .5(g)t^2
d = 22.89sin45(6.023) + .5(-9.8)(6.023)^2
d = 97 - 177.7
d = -80
Why am I getting -80 as my displacement? It's supposed to clear the fence. I had to obviously have done something wrong when calculating the Vi in the range.
Homework Statement
A batter hits a pitched ball when the center of the ball is 1.22m above the ground. The ball leaves the bat at an angle of 45 degress with the ground. With that launch, the ball should have a horizontal range (returning to the launch level) of 107m
(a) Does the ball clear a 7.32m high fence that is 97,5 n horizontally from the launch point? (b) At the fence, what is the distance between the fence top and the ball center?
Homework Equations
y = (tan theta)x - (g(x^2))/(2(vicos45)^2)
R = (2Vi^2/g)(Sin 2 Theta)
The Attempt at a Solution
107 = (2Vo^2/g) * Sin 2(45)
107 * g = 2Vo^2 * 1
1048.6 / 2 = Vo^2
524.3 = Vo^2
22.89 = vo^2
y = (tan 45)(97.5) - (9.8(97.5)^2) / ((2)(-524.3)(cos45)^2)
y = 97.5 - 177.58
y = -80
The ball clears the fence, so why am I getting -80 for the y coordinate?
Okay, how about this... Let's try using basic kinematics
vix = d/t
t = d/vix
t = 97.5/(22.89cos45)
t = 6.023
d = Viy(t) + .5(g)t^2
d = 22.89sin45(6.023) + .5(-9.8)(6.023)^2
d = 97 - 177.7
d = -80
Why am I getting -80 as my displacement? It's supposed to clear the fence. I had to obviously have done something wrong when calculating the Vi in the range.