Calculate the frequency spectrum of sound power radiating from a thin/thick plate or shell under the following conditions. (1)you can arbitrarily choose vibrating plate or shell. (2)you are expected to execute modal analysis, forced vibration analysis and estimation of sound radiation power however you can assume any mode shapes or natural frequencies if it will be difficult to calculate exact or approximated vibration modes. (3) you can select mechanical point excitation or sound excitation with arbitrary frequency spectrum of excitation force. (4) you also assume modal total loss factors even if they are constant. (5) illustrate mode shapes with natural frequencies and frequency spectra of loss factors, input power and sound radiation power.

question1

1,000 tons

question2

3: 8

question 3

store d

step-by-step explanation:

no. dot product   =0 when vecs at right angles

the design of a ski jumping suit involves a trade-off between giving the skiers lift to get higher jumps and ensuring the skier does not face a lot of drag before the jump itself. an expansive suit may to lift the skier higher, but at the same time, it will also increase the air resistance. higher air resistance as the skier goes down the slope limits the speed of the jump. a big suit also increases the risk of losing balance or control, especially if there's a strong gust of wind. while technologically enhanced suits a lot, clothing is not the only factor in a ski jumper’s success. gathering speed while skiing down the slope, ensuring good speed on the ramp, and maintaining good body posture and form in the air all contribute to a ski jumper's success.