x Course Home MasteringPhysics: HW4 M Your Physics answer is ready. - sa X b Answered: A jet pilot takes his air X session.masteringphysics.com/myct/itemView?offset=next&assignmentProblemiD=135028808 Apps (1) NN P4... YouTube to MP3 Co.. phone cover for mo... AGARWAL-PHY-166 KHW4 Item 12 The space shuttle releases a satellite into a circular orbit 710 km above the Earth. Part A How fast must the shuttle be moving (relative to Earth) when the release occurs? Express your answer using three significant figures and include the appropriate units. Value Units Submit Request Answer Provide Feedback II

The mean flee path for helium at a certain temperature and pressure is 2.10107 m. The radius of a helium atom can be taken as 1.101011 m. What is the measure of the density of helium under those conditions (a) in molecules per cubic meter and (b) in moles per cubic meter? `

Let's stop ignoring the greenhouse effect and incorporate it into the previous problem in a very rough way. Assume the atmosphere is a single layer, a spherical shell around Earth, with an emissivity e 0.77 (chosen simply to give the light answer) at infrared wavelengths emitted by Earth and by the atmosphere. However, the atmosphere is transparent to the Sun's radiation (that is, assume the radiation is at visible wavelengths with no infrared), so the Sun's radiation leaches the surface. The greenhouse effect comes from the difference between the atmosphere transmission of visible light and its rather strong absorption of infrared. Note that the atmosphere's radius is not significantly different from Earth's, but since the atmosphere is a layer above Earth, it emits radiation both upward and downward, so it has twice Earth's area. There are three radiative energy transfers in this problem: solar radiation absorbed by Earth's surface; infrared radiation from the surface, which is absorbed by the atmosphere according to its emissivity; and infrared radiation from the atmosphere, half of which is absorbed by Earth and half of which goes out into space. Apply the method of the previous problem to get an equation for Earth 's surface and one for the atmosphere, and solve them for the two unknown temperatures, surface and atmosphere. a. In terms of Earth's radius, the constant , and the unknown temperature Ts of the surface, what is the power of the infrared radiation from the surface? b. What is the power of Earth 's radiation absorbed by the atmosphere? c. In terms of the unknown temperature Te of the atmosphere, what is the power radiated from the atmosphere? d. Write an equation that says the power of the radiation the atmosphere absorbs from Earth equals the of the radiation it emits. e. Half of the power radiated by the atmosphere hits Earth. Write an equation that says that the power Earth absorbs from the atmosphere and the Sun equals the power that it emits. f. Solve your two equations for the unknown temperature of Earth. For steps that make this model less crude, see for example (https://openstaxcollege.org/l/21paulgormlec) by Paul O'Gorrnan.

(a) Suppose that a person has an average heart rate of 72.0 beats/min. How many beats does he or she have in 2.0 y? (b) In 2.00 y? (c) In 2.000 y?

What is critical temperature Tc? Do all materials have a critical temperature? Explain why or why not.

Check Your Understanding If a=3+4i , what is the product a* a?

Estimates and Fermi Calculations Assuming the human body is made primarily of water, estimate the volume of a person.

(a) Suppose a meter Stick made of steel and one made of invar (an alloy of iron and nickel) are the same length at 0C. What is their difference in length at 22.0C ? (b) Repeat the calculation for two 30.0mlong surveyor's tapes.

A marathon runner completes a 42.188-km course in 2 h, 30 min, and 12s. There is an uncertainty of 25 m in the distance traveled and an uncertainty of 1 s in the elapsed time. (a) Calculate the percent uncertainty in the distance. (b) Calculate the percent uncertainty in the elapsed time. (C) What is the average speed in meters per second? (d) What is the uncertainty in the average speed?

A light balloon is filled with 400 m3 of helium at atmospheric pressure. (a) At 0C, the balloon can lift a payload of what mass? (b) What If? In Table 15.1, observe that the density of hydrogen is nearly half the density of helium. What load can the balloon lift if filled with hydrogen?