The scale height of an atmosphere is a measure of how tightly a planet holds onto its atmospheric gases. this is a very useful concept because it balances the atmosphere's thermal energy of expansion against gravity's compression. as a rule of thumb, planets with larger scale heights struggle more to hold onto their atmospheres than planets with smaller scale heights. the scale height of an atmosphere can be computed as h = kt/g where k is a measure of the energy density of the atmosphere (which depends upon the average molecular mass of the atmosphere) expressed in units of j/kg k, t is the planet's surface temperature in units of k, and g is the gravitational acceleration at the planet's surface in units of m/s2. (note that when the calculation is performed in these units, the resultant scale height is measured in meters. often, we find it more convenient to convert the scale height into units of kilometers.) venus has an energy density k = 191.7 j/kg k, a surface temperature t = 750 k and a surface gravitational acceleration g = 8.87 m/s2. what is the scale height of venus in units of kilometers?

Adiver in midair has an angular velocity of 6.0 rad/s and a moment of inertia of 1.2 kg·m2. he then pulls is arms and legs into a tuck position and his angular velocity increases to 12 rad/s. the net external torque acting on the diver is zero. what is his moment of inertia in the tuck position?

While studying chemical reactions and conservation of matter, sarah's class conducted a variety of experiments. sarah and her lab partner found the mass of a wax candle and placed the candle in a flask. the students lit the candle and let it burn to completion. all that was left was wax and charred candle wick. per their teacher's instructions, the students found the mass of the products. their data can be seen in the data table. formulate a hypothesis the students could test to explain why the experiment did not support the law of conservation of matter. a) the students could repeat the experiment using different candles; there might have been a flaw in the candle. b) the experiment should be repeatable. the students should run several trials and then take an average of the after mass in each trial. c) the students should have someone in the class check their measurement skills as they repeat the experiment. they may have made an error using the balance. d) the students should burn the candle in a container that has some type of lid so that any gas that is a product of the reaction can be contained and massed. submit

The ozone hole appears in antarctica during