The color of a star depends on its (composition, distance, temperature), (red, white, yellow ) and -colored stars are the coolest.

The extremely high temperatures needed to trigger nuclear fusion are proposed to be generated by laser irradiating a spherical pellet of deuterium and tritium fuel of diameter 1.8 mm. (a) determine the maximum fuel temperature that can be achieved by irradiating the pellet with 200 lasers, each producing a power of 550 w. the pellet has an absorptivity 0.3 and emissivity 0.8.

Askydiver weighing 140 lb (including equipment) falls vertically downward from an altitude of 19,000 ft and opens the parachute after 18 s of free fall. assume that the force of air resistance, which is directed opposite to the velocity, is of magnitude 0.55|v| when the parachute is closed and is of magnitude 14|v| when the parachute is open, where the velocity v is measured in ft/s. assume that acceleration due to gravity has magnitude 32 ft/s/s; remember that weight is the product of mass and gravitational acceleration. (a) find the speed of the skydiver when the parachute opens. (b) find the distance fallen before the parachute opens. (c) what is the limiting velocity vl after the parachute opens? (d) determine how long the sky diver is in the air after the parachute opens. (e) plot the graph of velocity versus time from the beginning of the fall until the skydiver reaches the ground.

A40.0 l tank of ammonia has a pressure of 12.7 kpa. calculate the. volume of the ammonia if it’s pressure is changed to 8.4 kpa while its temperature remains constant.