Question

A man weighs 840N on earth surface and 640N on another planet. Calculate planet's gravitational force

Answer 1

Hey, there!

Here's your answer.

Let the mass of the man be 'm' kg

Since mass remains unaffected from wherever you are, mass of man on Earth = mass of man on the other planet = m kg.

Weight = mass × acceleration due to gravity

For Earth, W = m ×g = 840 N

For the other planet, W' = m × g' = 640 N

☛ Now, divide both the equations,

$\frac{W}{W'} = \frac{m \times g}{m \times g'} = \frac{840}{640} \\ \\ \frac{g}{g'} = \frac{21}{16} \\ \\ g' = \frac{16}{21} g = 7.619m {s}^{ - 2} (approx.)$

Hope that helps.

Thanks.