Water is being heated in a closed pan on top of a range while being stirred by a paddle wheel. during the process, 9.5 kj of heat is transferred to the water, and 5.4 kj of heat is lost to the surrounding air. the paddle-wheel work input is 579 n∙m. determine the mass in the system if its change in specific internal energy is 5 kj/kg.

To place a communications satellite into a geosynchronous orbit at an altitude of 22,240 mi above the surface of the earth, the satellite first is released from a space shuttle , which is in a circular orbit at an altitude of 185 mi, and then is propelled by an upper-stage booster to its final altitude. as the satellite passes through a, the booster's motor is fired to insert the satellite into an elliptic transfer orbit. the booster is again fired at b to insert the satellite into a geosynchronous orbit. knowing that the second firing increases the speed of the satellite by 4810ft/s, determine (a.) the speed of the satellite as it approaches b on the elliptic transfer orbit, (b.) the increase in speed resulting from the first firing at a.

Relative to the ground below, how many joules of potential energy does a 1000-kg boulder have at the top of a 5-m ledge?

Aheavy boy and a lightweight girl are balanced on a massless seesaw. the boy moves backward, increasing his distance from the pivot point. what happens to the seesaw? it is impossible to predict without knowing additional information. the side the boy is sitting on will tilt downward. the side the girl is sitting on will tilt downward. nothing; the seesaw will remain balanced.