Hi all, I'm new here. So anyways, I have been studying for exams by going through my old tests, and I found a question from one of them that I cant solve...I hope someone can help me.(adsbygoogle = window.adsbygoogle || []).push({});

1. A person stands on a set of bathroom scales which have been calibrates in newtons. The scales read 500N (assume 3 sig figs)

A)What would the reading be if the same person stood on the scales on a planet where the gravitational field strength,gis 14 N/kg?

B) If this planet had a mass of 7.0 x 10^24 kg, what would its radius be?

C) What mass would this person weigh at an altitude of 2.8 x 10^6 m above the planet's surface?

2. Relevant equations

Well I used the equations for

A)

F=mg

B)

F = G (mass planet) (mass object) / d^2

C) I don't know what equation to use...

So what I did:

for A) I used Fg=mg

so:

Fg = mg

500 = m (9.8)

m = 51

then I substituted for the planet.

Fg = m(14)

Fg = (51)(14)

Fg = 714

For B) I used F = G (mass planet) (mass object) / d^2

so,

Fg = 6.67 x 10^-9 *7.0x10^24 / d^2

d^2 = 4.669

d = 2160789.4 km

For C) given height, I dont know what equation to use.

So really, I don't know whether I used my equations correctly, so I would appreciate someone to point out my errors.

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# Homework Help: Gravitational Force

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