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A ball of mass 0:4 kg, initially at rest, is
kicked directly toward a fence from a point
20 m away, as shown below.
The velocity of the ball as it leaves the
kicker's foot is 17 m=s at angle of 51 ± above
the horizontal. The top of the fence is 7 m
high. The kicker's foot is in contact with the
ball for 0:04 s. The ball hits nothing while in
°ight and air resistance is negligible.
The acceleration due to gravity is 9:8 m=s2.


What is the vertical component of the velocity
when the ball reaches the plane of the fence?
Answer in units of m=s.

2007-10-15 12:37:46 · 2 answers · asked by dojorno5 2 in Science & Mathematics Mathematics

2 answers

First we want to know the vert and hor components of initial velocity v0. Then hor vel and distance give us the time, then time and g give us velocity.
v0x (hor) = v0cos(theta)
v0y (vert) = v0sin(theta)
flight time to plane of fence t = x/v0x
vy(t) = v0y - gt
Note that the height of the fence and the mass of the ball are irrelevant.

2007-10-18 12:42:00 · answer #1 · answered by kirchwey 7 · 0 0

8959508930300303095965959595.9095000303003039908277891790613048347-3498 meeterz a sec


really thiz is a phyzizc question and im only in calculuz

2007-10-15 19:44:42 · answer #2 · answered by Sharpies134 4 · 0 3

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