Transcript pptx

Water Copters
𝜕𝑃
𝐹 ==𝑚𝑚𝑎𝑎
𝜕𝑡
𝜕𝑃
=0
𝜕𝑡
⟹ 𝑃𝑧,𝜒 = 𝑃𝑧,𝑎𝑖𝑟
𝑚𝜒 𝑔 Δ𝑡 = 𝑚𝑎𝑖𝑟 𝑣𝑎𝑖𝑟 = 𝜌𝑎𝑖𝑟 𝐴𝜒 𝑣𝑎𝑖𝑟 Δ𝑡 𝑣𝑎𝑖𝑟
2
𝑣𝑎𝑖𝑟
=
𝑚𝜒 𝑔
𝜌𝑎𝑖𝑟 𝐴𝜒
Some reference
• 𝑣𝑤𝑎𝑡𝑒𝑟 = 6.5
𝑚
𝑠𝑒𝑐
~ 23
𝑘𝑚
ℎ𝑟
• 5K world record: 12:37.35 -> 𝑣𝑊𝑅 = 6.6
• 800m ER: 1:41.91 -> 𝑣𝑊𝑅 = 7.92
𝑚
• 1000m WR: 2:11.96 -> 𝑣𝑊𝑅 = 7.57
𝑚
𝑠𝑒𝑐
𝑚
𝑠𝑒𝑐
𝑠𝑒𝑐
Water-Polo periods:
• 4 quarter game
• Each quarter = 8 minutes of actual play time.
• Time-outs: 2 minutes, 5 minutes half-time.
• 50-60 minutes of actual in-water time.
How much swimming is involved?
• Water polo swimming
• Swimming = Resting?!!
• At the MOST 30% of time.
Water polo violence