Physics

A place kicker must kick the football from a point 34.2 m from the goal and
clear a bar 3.00 m above the ground. The ball leaves the ground with a speed of 20.0 m/s at an angle of 53.0 degrees above the horizontal.
(a) By how much (m) does the ball clear (positive value) or fall short (negative value) of the cross bar? (This is vertical distance above or below the cross bar.)
(b) When it gets to the cross bar, what is the vertical component of the ball's velocity (m/s)? (Is it rising or falling-pay attention to the sign?)

1. 1
1. (a) The horizontal velocity component is 20 cos 53 = 12.036 m/s. To travel 34.2 m to the goal post requires 34.2/12.036 = 2.84 seconds. Its height y at that time is
y(t=2.84) = 20*sin53*t - (g/2)t^2
= 5.84 m. That would be 2.84 m above the cross bar.

(2) V(t=2.84) = 20sin53 - g*t = 15.97 - 27.83 = -11.86 m/s. So the football is falling

posted by drwls

Similar Questions

1. physics

A place kicker must kick a football from a point 38.2 m from a goal. As a result of the kick, the ball must clear the crossbar, which is 3.05 m high. When kicked the ball leaves the ground with a speed of 20.6 m/s at an angle of
2. Physics

A place kicker must kick a football from a point 31.2 m from a goal. As a result of the kick, the ball must clear the crossbar, which is 3.05 m high. When kicked the ball leaves the ground with a speed of 21.3 m/s at an angle of
3. Physics

A place kicker must kick a football from a point 31.2 m from a goal. As a result of the kick, the ball must clear the crossbar, which is 3.05 m high. When kicked the ball leaves the ground with a speed of 21.3 m/s at an angle of
4. physics

a place kicker must kick a football from a point 32.0 m from the goal. As a resultof the kick, the ball must clear the crossbar, which is 3.05 m high. When kicked, the ball leaves the ground with a speed of 23.0 m/s at an angle of
5. Physics

A place kicker must kick a football from a point 33.0 m (about 36 yd) from the goal. As a result of the kick, the ball must clear the crossbar, which is 3.05 m high. When kicked, the ball leaves the ground with a speed of 20.0 m/s
6. physics

A place kicker must kick a football from a point 34.0 m (about 37 yd) from the goal. As a result of the kick, the ball must clear the crossbar, which is 3.05 m high. When kicked, the ball leaves the ground with a speed of 21.0 m/s
7. Physics

A place kicker must kick a football from a point 37.1 m from a goal. As a result of the kick, the ball must clear the crossbar, which is 3.05 m high. When kicked the ball leaves the ground with a speed of 19.8 m/s at an angle of
8. physics

I know this has been posted many times but I keep trying and cannot get the right answer, A place kicker must kick a football from a point 39.9 m from a goal. As a result of the kick, the ball must clear the crossbar, which is
9. physics

I know this has been posted many times but I keep trying and cannot get the right answer, A place kicker must kick a football from a point 39.9 m from a goal. As a result of the kick, the ball must clear the crossbar, which is
10. physics

A place kicker must kick a football from a point 36.0 meters (about 40yds)from the goal. as a result of the kick, the ball must clear the crossbar, which is 3.05 meters high. When kicked the ball leaves the ground with a speed of
11. physics

A place kicker must kick a football from a point 32.2 m from a goal. As a result of the kick, the ball must clear the crossbar, which is 3.05 m high. When kicked the ball leaves the ground with a speed of 20.8 m/s at an angle of

More Similar Questions