Question

(3) What will be the gravitational force
60 kg man on the Moon, Mars and Jupiter? A
they the same? Why?
M (Moon) = 7.36 x 1022 kg, R (Moon)=1.74 x 106
M (Mars) = 6.4 x 1023 kg, R (Mars) = 3.395 x 106
full explain please
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Answer 1

Data

Looking on page 178, we see that the mass of the Moon is 7.35 X 1022 kilograms, and the radius of the Moon is 1738 kilometers

Equation

We must use the density formula: density = mass / volume

Unit Conversion

Nothing is in the right units! We must convert the mass into grams:

MMoon = 7.35X 1022 kg X 1000 gm / kg = 7.35 X 1025 grams

We must convert the radius into centimeters:

RMoon = 1738 km X (1000m / km) X (100cm / m) = 1.738 X 108 cm

Computation

So V = (4/3)(pi)R3 = (4/3)(3.14)(1.738 X 108 cm)3

V = 2.20 X 1025 cm3

And Density = M / V = 7.35 X 1025 gm / 2.20 X 1025 cm3

density = 3.34 gm/cm3

The Answer

The density of the Moon in 3.34 grams per cubic centimeter, in good agreement with the value in the book.