2. You are on in-line skates at the top of a small hill. Your potential energy is equal to
1,000. J. The last time you checked, your
mass was 60.0 kg.
a. What is your weight in newtons?
b. What is the height of the hill?
c. If you start rolling down this hill, your
potential energy will be converted to
kinetic energy. At the bottom of the hill,
your kinetic energy will be equal to your
potential energy at the top. Calculate
your speed at the bottom of the hill,
ka hallint

As part of an industrial process, air as an ideal gas at 10 bar, 400k expands at steady state through a valve to a pressure of 4 bar. the mass flow rate of air is 0.5 kg/s. the air then passes through a heat exchanger where it is cooled to a temperature of 295k with negligible change in pressure. the valve can be modeled as a throttling process, and kinetic and potential energy effects can be neglected. (a) for a control volume enclosing the valve and heat exchanger and enough of the local surroundings that the heat transfer occurs at the ambient temperature of 295 k, determine the rate of entropy production, in kw/k. (b) if the expansion valve were replaced by an adiabatic turbine operating isentropically, what would be the entropy production? compare the results of parts (a) and (b) and discuss.

Identify some abiotic characteristics of the tundra biome.

The lift raises a car of mass 850 kg to a height of 2.1 m. it uses a force of 8330 n and takes 4 seconds to raise the car. what is the power of the lift?