Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

1) Two equal-mass stars maintain a constant distance apart of4.8E10 m and rotate

ID: 1674953 • Letter: 1

Question

1) Two equal-mass stars maintain a constant distance apart of4.8E10 m and rotate about the point midway between them. They makeone revolution every 2.6 yr. What is the mass (in kg) of eachstar? (Answer: 4.85x10^27) 2) A portable animal cage weighs 1200 N and rests on thefloor, off its wheels. How much work (in J) is required to drag it(without wheels) at constant speed 5.1 m along the horizontal flooragainst a friction force of 806 N? ( Answer:4.11x10^3) 1) Two equal-mass stars maintain a constant distance apart of4.8E10 m and rotate about the point midway between them. They makeone revolution every 2.6 yr. What is the mass (in kg) of eachstar? (Answer: 4.85x10^27) 2) A portable animal cage weighs 1200 N and rests on thefloor, off its wheels. How much work (in J) is required to drag it(without wheels) at constant speed 5.1 m along the horizontal flooragainst a friction force of 806 N? ( Answer:4.11x10^3) 2) A portable animal cage weighs 1200 N and rests on thefloor, off its wheels. How much work (in J) is required to drag it(without wheels) at constant speed 5.1 m along the horizontal flooragainst a friction force of 806 N? ( Answer:4.11x10^3)

Explanation / Answer

1. The gravitational force is the centripetal force:         F = GMM/R2 =M2(R/2) =M(42/T2)(R/2)         M =(22R3)/(GT2) = 4.86 E27kg 2. At a constant speed: F = Ffriction = 806 N     Work required:       W = F.d = 806*5.1 = 4.11E3 N