1. Cylinder contains 0.1 mol of ideal gas at a pressure of 2 atm and temperature of 300 K. The volume of the cylinder is 1.25 x 10^-3 m3. When the gas is heated from 300K to 350K, what is the change in internal energy of the gas?(adsbygoogle = window.adsbygoogle || []).push({});

--->(I think the equation is Q=delta U + W but I don't know how to proceed from there.)

2. So of all the properties of waves (speed, amplitude, wavelength and frequency) which one is independent of the others?

--> Is it amplitude?

3. A train is blowing its whistle at 860Hz while traveling at a speed of 40m/s. The speed of sound is 340 m/s. What is the frequency heard by a stationary observer in front of the train?

---> I used the equation, f'= f (1/1+ or - Vs/V) and I got 769 Hz as the answer but I'd like to confirm with someone whether I am doing it correctly.

Thanks!

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# What is the change in internal energy of the gas?

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