Find the magnitude of the gravitational force exerted on a 66.5 kg astronaut on the surface of planet x if the planet has a radius of 4.40 x 10⁶ m and a mass of 8.43 x 10²³ kg. (use g= 6.67 x 10⁻¹¹ nm/kg²)

An insulated thermos contains 148 g of water at 72.7 ˚c. you put in a 11.7 g ice cube at 0.00 ˚c to form a system of ice + original water. the specific heat of liquid water is 4190 j/kg•k; and the heat of fusion of water is 333 kj/kg. what is the net entropy change of the system from then until the system reaches the final (equilibrium) temperature?