useful bounds can be set on the pressure at the center of star without detailed stellar structure calculations 4. a. show that in hydrostatic equilibrium the function gm(r)2 8rr4 decreases with r. hence, show that the central pressure satisfies the inequality p. go4/3m2/3 c613 where m* is the mass of the whole star. b. if you assume that the density ρ(r) decreases with r, it is possible to derive a tighter lower bound and, in addition, a useful upper bound for the central pressure. show that gō4/3m2/3 in addition, show that 1/3 nd誾 gp: /3m 4/3 42/3 where pc is the central density

If an inclined plane is 5 m long and 2 m high, what is its mechanical advantage? a. 2.5 b. 3 c. 7 d. 10

1.in one challenge on the titan games, competitors have to lift 200 pounds up a long ramp. angel is able to move the weight in 42 seconds. anthony gets it done in only 38 seconds. which statement is true? angel has more power than anthony. angel does more work than anthony. anthony does more work than angel. anthony has more power than angel. 2.a mountain climber exerts 41,000 j of work to climb a cliff. how much power does the climber need if she wants to finish in only 500 seconds? power = work / time 20,500,000 watts 82 watts 0.0122 watts 41,500 watts 3.your family is moving to a new apartment. while lifting a box 83 joules of work is done to put the box on a truck, you exert an upward force of 75 n for 3 s. how much power is required to do this? (hint: you only need two of the 3 numbers given! ) power = work / time 249 watts 25 watts 2075 watts 27.7 watts

1. jay fills a wagon with sand (about 20 kg) and pulls it with a rope 30 m along the beach. he holds the rope 25° above the horizontal. the rope exerts a 20-n tension force on the wagon. how much work does the rope do on the wagon?