Question1

A space station is constructed in the shape of a wheel 20 in diameter, with essentially all of its 5.1×105 mass at the rim. Once the station is completed, it is set rotating at a rate that requires an object at the rim to have radial acceleration, thereby simulating Earth's surface gravity. This is proficient using two small rockets, each with 100 thrust which are mounted on the rim of the station.

Question2

At a factory, a noon whistle is sounding with a frequency of 486 Hz. since a car travelling at 81 km/h approaches the factory; driver hears the whistle at frequency fi. After driving past factory, the driver hears frequency ff. What is modify in frequency ff - fi heard by the driver? (Suppose a temperature of 20° C.)