How to find the acceleration of a random planet

[justinbaker]

here is the question,

the mysterious planet pyramid travels around its sun in a circular orbit. The radius of this planet is 2.69e^7 m and the mass is 3.06e^25 kg . The radius of orbit of pyramid is 1.15e^11 m and the period is 6.34e^7 s . The mass of pyramids sun is 9.22e^31 and the radius of the sun is 1.50e^9 m . What is the acceleration of gravity on pyramid? (m/s^2)


i thought you could use the formula v=(2(pi)r)/T and plug this into F=m(v^2/r) since the only force is gravity towards the sun.

But my answer comes out to be 3.45e^22

this seems a little high, any help? thanks guys

 

[Doc Al]

You have the mass and the radius of the planet. Use Newton's law of gravity to find the acceleration due to gravity at the planet's surface.

 

[justinbaker]

dont i need to use the period somewhere in this problem?

 

[Doc Al]

dont i need to use the period somewhere in this problem?

Not if the problem is to find the acceleration due to gravity on that planet's surface. (Is that the problem?)