On an ice rink, two skaters of equal mass grab hands and spin in a mutual circle once every 2.9 s .If we assume their arms are each 0.85 m long and their individual masses are 61.0 kg , how hard are they pulling on one another?Express your answer to two significant figures and include the appropriate units.

Blank liquids and gases exert a buoyant force on objects placed in them

In a heat engine if 1000 j of heat enters the system the piston does 500 j of work, what is the final internal energy of the system if the initial energy was 2000 j? 1. write the equation 2.list out your known variables 3.plug the numbers into the equations 4.solve 5.write your solution statement that includes initial energy and final

The sun’s mass is 2.0×10^ 30 kg, its radius is 7.0×10 5 km, and it has a rotational period of approximately 28 days. if the sun should collapse into a white dwarf of radius 3.5×10 3 km, what would its period be if no mass were ejected and a sphere of uniform density can model the sun both before and after?