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ian_durrant
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[SOLVED] Kinematics in 2-dimesions
A soccer player kicks the ball toward a goal that is 25.0 m in front of him. The ball leaves his foot at a speed of 19.2 m/s and an angle of 65.8 ° above the ground. Find the speed of the ball when the goalie catches it in front of the net. (Note: The answer is not 19.2 m/s.)
x=V(0)t+(1/2)gt^2
V^2=V(0)^2+2gy
V= sqrt(Vx^2+Vy^2)
Ok let me define all the variables I've got so far
V(0)= 19.2
Vx0= 7.87
x= 25 (12.5 for one half)
gx= 0? (not so sure about this one)
Vx= ?(at top of apex )
Vy= 0 (at top of apex)
gy=-9.8
y= 15.626
Vy0= 17.5 (initial y veolicty)
Ok so the first thing I did was find the inital velocity for the x and y componets using sine and cosine, so
V0x= 19.2cos65.8= 7.87
V0y=19.2sin65.8= 17.5
I then used my inital y velocity to find out the heigth (y distance) of the shot
Vy^2= Vy0^2+2gy
0= (17.5)^2+2(-9.8)y
y= 15.625
I'm unsure where to go now in order to out the speed of the ball when the goalie catches it i know that V= sqrt (Vx^2+Vy^2). Should i try and figure out the two final velocities and then plug them into that equation?
Homework Statement
A soccer player kicks the ball toward a goal that is 25.0 m in front of him. The ball leaves his foot at a speed of 19.2 m/s and an angle of 65.8 ° above the ground. Find the speed of the ball when the goalie catches it in front of the net. (Note: The answer is not 19.2 m/s.)
Homework Equations
x=V(0)t+(1/2)gt^2
V^2=V(0)^2+2gy
V= sqrt(Vx^2+Vy^2)
The Attempt at a Solution
Ok let me define all the variables I've got so far
V(0)= 19.2
Vx0= 7.87
x= 25 (12.5 for one half)
gx= 0? (not so sure about this one)
Vx= ?(at top of apex )
Vy= 0 (at top of apex)
gy=-9.8
y= 15.626
Vy0= 17.5 (initial y veolicty)
Ok so the first thing I did was find the inital velocity for the x and y componets using sine and cosine, so
V0x= 19.2cos65.8= 7.87
V0y=19.2sin65.8= 17.5
I then used my inital y velocity to find out the heigth (y distance) of the shot
Vy^2= Vy0^2+2gy
0= (17.5)^2+2(-9.8)y
y= 15.625
I'm unsure where to go now in order to out the speed of the ball when the goalie catches it i know that V= sqrt (Vx^2+Vy^2). Should i try and figure out the two final velocities and then plug them into that equation?
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