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Need Help With Physics Problem Involving Work and Power?

You are asked to design a construction crane that is capable of lifting a mass of 5,000 kg (5 metric tons) from the ground to the top of a 65 m high building in 30 secondsWhat power should you specify for the motor that lifts the load, in horsepower? Note 1 hp 746 Watts 746 Joules/secondAverage power is defined to be the work done by a force divided by the time it took to do that work,P_avg W/Delta(t)Instantaneous power is the rate at which you are doing workP dW/dt F dx /dt F v,where dx, F and v are the infinitesimal displacement vector, the force vector, and the velocity vector, dt is the infinitesimal elapsed time, and the quot;.quot; above is the dot (or scalar) product of the vectors.

Answer:

There is a expanding foam insulation which a professional would do for you.Have it sprayed between the rafters,underside of roof.When it snows,when it stops snowing for awhile,the snow on your roof should still be there until it warms up outside.Get the highest R value pink insulation and build up what your already have.
.you should keep insulation from around ceiling fixtures, especially halogen because of the heat they generateSome are designed for direct contact but, unless you know that for sure, give it some breathing roomThere's two reasons: naturally the fire hazard from direct contact and the second is that insulation around the fixture would hold heat inside and drastically shorten the life of the fixture and wiringIt would make the insulation of the house wiring very brittle in a short period of time causing a possible fire hazard.
Go Pink! Cellulose is green, being a recycled product, but has a draw back no one is willing to talk aboutIt makes great litter for ratsAnd, it's flammableThe pink stuff you can put in yourselfThe cellulose has to be shot in using special equipmentIt settles and packs in over time and looses thermal efficiancyThe pink won't do that6 inches stays 6 inches.
I can't speak for R.I., but I'm a builder in Texas, where we have been in the high 90's low 100's for monthsBlown in is betterIt keeps the heat out in the summer the heat in in the winterAlso consider that it's newer technology, so it's inherently going to be an improvement on the old stuffBe wary of something called cocoon insulationit's very new and sometimes smells like ammoniaGood luck.
Power P Work/Time P mgh/t where m mass to be lifted 5000 kg (given) g acceleration due to gravity 9.8 m/sec (constant) h lifting height 65 m t 30 secSubstituting values, Power (5000)(9.8)(65)/30 Power 106,166.7 joules/sec 106,166.7 watts Power 106,166.7/746 Power 142.3 hpAssuming a crane efficiency of, say, 75%, then the motor must be 142.3/0.75 189.75 hpNOTE: I would recommend a 200-hp motor for this operation.

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