A54.0 kg ice skater spins about a vertical axis through her body with her arms horizontally outstretched, making 2.50 turns each second. the distance from one hand to the other is 1.5 m. biometric measurements indicate that each hand typically makes up about 1.25 % of body weight. part a)
what horizontal force must her wrist exert on her hand?
part b)
express the force in part (a) as a multiple of the weight of her hand.

Calculate the work done by an external agent during an isothermal compression of 1.00 mol of oxygen from a volume of 22.4 l at 10∘c and 1.0 atm pressure to 16.8l

Athin electrical heater is inserted between a long circular rod and a concentric tube with inner and outer radii of 20 and 40 mm. the rod (a) has a thermal conductivity of ka = 0.15 w/(m*k), while the tube (b) has a thermal conductivity of kb = 0.8 w/(m*k) and its outer surface is subjected to convection with a fluid of temperature t= -15°c and heat transfer coefficient 60 w/(m2 *k). the thermal contact resistance between the cylinder surfaces and the heater is negligible. (a) determine the electrical power per unit length of the cylinders (w/m) that is required to maintain the outer surface of cylinder b at 15°c. (b) what is the temperature at the center of cylinder a?

What kind of air would be characteristic of a continental polar air mass? o a cold, dryob. warm, humido c. warm, dryo d. cold, wet