Projectile motion question

1. Nov 4, 2004

hobo

When David Ortiz hit a homerun over the 12m high "Green Monster' fence at Fenway park 100m away from home plate, the ball was hit 1.0m above the ground at an angle of 35° above horizontal. What was the minumum speed of the batted ball?

dx = 100m
Vx = Xcos35°
Vox= Xcos35°
ax = 0
dy = 11m
vy = ?
voy = ?
ay = -9.8m/s/s
t = ?

That is as far as I have gotten. I have only had experience with three missing variables, not five. How do I even start this question?

2. Nov 4, 2004

Parth Dave

Suppose we make the initial velocity Vo. Then the initial x direction velocity is Vocos(35) and the y is Vosin(35). Can you write an equation for the displacement in the x and y directions based on your acceleration and initial velocity?

3. Nov 4, 2004

KFunk

If you're assuming that its path is parabolic and you are using some of the simple physics formulae then:

v^2= u^2 + 2as
(take out 'u^2' because you are calculating the vertical velocity once it reaches 1 meter above the ground after having accelerated from the point above the fence where it's vertical velocity component was equal to zero)

v(vertical component) = sqrt(2 x acceleration due to gravity x 11)

then you could work in the V(initial) = V_y (initial)/ sin 35 etc. etc.

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