Cuando el estudiante mantiene extendidos sus brazos horizontalmente, los objetos distan a 1.0 m respecto al eje de rotación y éste gira con una rapidez angular de 0.75 rad/s; el momento de inercia del estudiante y la silla, tienen y una magnitud constante de 3 kg .m². Suponiendo que el estudiante jalará los objetos horizontalmente a 0.30 m del eje de rotación, determinar: a) La nueva rapidez angular del estudiante. b) La energía cinética del estudiante antes y después de que los objetos sean aproximados al eje de rotación

The device shows the relative humidity at 22°c. what’s the water vapor density if the maximum water vapor in air at this temperature is 20 grams/cubic meter? a device showing that at 22 degrees celsius the relative humidity is 58%. a. 11.6% b. 11.6 g/m3 c. 12.76% d. 12.76 g/m3 reset next

4.at 0 ºc, some amount of energy is required to change 1 kg of water from a solid into a liquid. if you had a 2 kg piece of ice, what effect would this have on the amount of thermal energy required to change the water from a solid to a liquid? it would require more energy to change solid water into liquid water because there are more molecules in this larger piece of ice. it would still require the same amount of energy to change solid water into liquid water because the entire piece of ice would still gain the same amount of energy in each case. it would require energy to be removed from the 2 kg piece of ice. the larger piece of ice already has more total energy than the smaller piece of ice, so energy must be removed for the ice to become liquid. it would require less energy to change solid water into liquid water because the energy would spread through the ice more quickly and the ice already has a larger total amount of energy because it is larger than a 1 kg piece of ice.

Acarpenter is driving a 15.0-g steel nail into a board. his 1.00-kg hammer is moving at 8.50 m/s when it strikes the nail. half of the kinetic energy of the hammer is transformed into heat in the nail and does not flow out of the nail. what is the increase in temperature of the nail after the three blows that the carpenter needs to drive the nail in completely? the specific heat of steel is 448 j/kg ∙ k. a) 2.7 k b) 1.8 k c) 7.7 k d) 8.1 k e) 3.6 k