Question

You weigh 640 N.
What would you weigh if the Earth were five times as massive as it is and its radius were five times its present value?
Answer in units of N.

Answer 1

original acceleration due o gravity on earth's surface is,

g = (GM)/R²

New acceleration due o gravity on earth's surface is,

g' = (GM')/R'²

= (G(5M))/(5R)²

= (GM)/(5R²)

= g/5

Now, original weight is

W = mg = 640 N

So, new weight is,

W' = mg'

= m(g/5)

= (mg)/5

= (640 N)/5

= 128 N

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This concludes the answers. If there is any mistake or omission, let me know in the comments immediately and I will fix it....