An overhead 25-m-long, uninsulated industrial steam pipe of 100-mm diameter is routed through a building whose walls and air are at 25∘C. Pressurized steam maintains a pipe surface temperature of 150∘C, and the coefficient associated with natural convection is h=10W/m2⋅K. The surface emissivity is ε=0.8. (a) What is the rate of heat loss from the steam line? (b) If the steam is generated in a gas-fired boiler operating at an efficiency of ηf=0.90 and natural gas is priced at Cg=$0.02 per MJ, what is the annual cost of heat loss from the line?

An automobile of mass 2000 kg moving at 30 m/s is braked suddenly with a constant braking force of 10000 n. how far does the car travel before stopping?

Apulley with a mechanical advantage of 5 will require you to pull times the amount of rope. a. 1/5 b. 5 c. 10 d. 15

The ultracentrifuge is an important tool for separating and analyzing proteins. because of the enormous centripetal accelerations, the centrifuge must be carefully balanced, with each sample matched by a sample of identical mass on the opposite side. any difference in the masses of opposing samples creates a net force on the shaft of the rotor, potentially leading to a catastrophic failure of the apparatus. suppose a scientist makes a slight error in sample preparation and one sample has a mass 10 mg larger than the opposing sample. if the samples are 12 cm from the axis of the rotor and the ultracentrifuge spins at 70,000 rpm, what is the magnitude of the net force on the rotor due to the unbalanced samples? ( be thorough on your answer)