Rotational and Angular Speed

A turn-table on a frictionless vertical axis has a radius of 1.5 m and a moment of rotational inertia of 150 kgm^2. It is at rest until a 75 kg person who had been standing still (and who can be treated as a point), begins to walk around the rim at a speed of 2.0 m/s with respect to the turn-table. a) what is the speed of the person with respect to the Earth? b)How much work did the person do in bringing the turn-table up to speed?

Boiler saftey valves

NOTE: MOVED FROM MECHANICAL ENGINEERING TO PHYSICS BECAUSE MECHANICAL OTAs UNABLE TO ADDRESS IN TIME. An HRT boiler burning gas with 5.9MJ calorific value and 34m^2 of heating surface not exceeding 1200 kpa,needs safety valves.Find the code requirement for a)safety valve capacity b)max diameter of surface for connection c)max setting for any safety valve on this boiler? need step by step solution with answers. thanks..

Venturi meter readings sphere density.

NOTE: MOVED FROM MECHANICAL ENGINEERING TO PHYSICS BECAUSE MECHANICAL OTAs UNABLE TO ADDRESS IN TIME. 1a) A venturi meter has 0.02556m^3 of flow per second through its 45mm dia throat.If the pipe is 58mm in diameter,what will the differential reading of mercury across it be? b)A metal sphere 60mm in dia is submerged in oil with a relative density of 0.9.Need to find the density of the sphere.There is a downward force of 8.31N when the sphere is submerged? need step by step solutions. Thanks..

Conduction

In an electrically heated home, the temperature of the ground in contact with a concrete basement wall is 12.8 degrees Celsius. The temperature at the inside surface of the wall is 20.0 degrees Celsius. The wall is 0.10m thick and has an area of 9.0m^2. Assume one kilowatt hour of electrical energy costs $0.10. How many hours are required for one dollar's worth of energy to be conducted through the wall?

Conduction

A skier wears a jacket filled with goose down that is 15mm thick. Another skier wears a wool sweater that is 5.0mm thick. Both have the same surface area. Assuming the temperature difference between the inner and outer surfaces of each garment is the same, calculate the ration (wool/goose down) of the heat lost due to conduction during the same time interval.