- #1

roam

- 1,271

- 12

## Homework Statement

The diagram below illustrates the ballistic flight of circus daredevil, The Great Zacchini, over three ferris wheels, each 21.2 m high. Zacchini is launched at a speed of 27.6 m/s from the muzzle of the human cannon at an angle of 56.7 ° to the horizontal from a height of 1.6 m above the ground. The net in which he lands is located at the same height above the ground. The Ferris wheels are arranged an equal distance apart, the one closest to the cannon being displaced 24.1 m from the cannon's muzzle. For the purposes of the calculations below assume that air resistance is negligible and treat Zacchini as a point particle.

http://img510.imageshack.us/img510/793/imagebz.jpg [Broken]

**(a)**By how much does he clear the first Ferris wheel?

**(b)**If he reached his maximum elevation above the middle Ferris wheel what is his clearance above it?

## The Attempt at a Solution

**(a)**

[tex]v_{ix}=27.6 cos (56.7) = 15.15[/tex]

[tex]v_{iy}=27.6 sin (56.7) = 23[/tex]

[tex]x=vt \Rightarrow 24.1 = 15.15 t[/tex]

[tex]t=1.6[/tex]

[tex]y=v_{iy}t+\frac{1}{2}(9.81)(1.6)^2 = 49.35[/tex]

49.35 is the height it obtains when it is over the first Ferris wheel. Since the heigh of the Ferris wheel is 21.2 we have 49.35-21.2=28.15

But this is wrong because the correct answer has to be

**4.69**. So what are my mistakes?

**(b)**No idea how to get started!

Last edited by a moderator: