Posted by **Chan** on Sunday, May 15, 2011 at 11:10pm.

A simple pendulum has a period T on the surface of planet Earth. When taken to the surface of planet X, the same pendulum has a period 2T.

a) If the radius of planet X is 1/2 the radius of Earth, what is the mass of Planet X, relative to the mass of Earth?

b) Suppose a vertical mass and spring oscillator has a period T on Earth. What period would the oscillator have on planet X? Explain.

- Physics -
**drwls**, Sunday, May 15, 2011 at 11:31pm
a) If the period on planet X is 2T, the acceleration of gravity (g) at the surface is 4 times less than Earth's, because

Period = 2 pi sqrt(L/g)

Since g = GM/R^2, if g is 1/4 as large as Earth's, and R is half the Earth's radius, M is 1/16 of Earth's.

g(X) = g(earth)*[M(X)/M(earth)]*[Rearth/RX]^2

= g(earth)*(1/16)*2^2 = g(earth)/4

b) The period of a spring-mass oscillator system would not change. It does not depend upon gravity.

## Answer this Question

## Related Questions

- Physics (Please Help) - An astronaut lands on an alien planet. He places a ...
- Physics (Really need help with this) - An astronaut lands on an alien planet. He...
- Physics - A 21.0-kg satellite has a circular orbit with a period of 2.37 h and a...
- College Physics. - A pendulum has a period of 1.8 s. a) Its mass is doubled. ...
- Physics - 3. An astronaut lands on an alien planet. He places a pendulum (L = 0....
- physics - An object rests on the surface of planet y. Its mass is unknown. Find...
- physics - A 17.0-kg satellite has a circular orbit with a period of 2.31 h and a...
- physics help 3!! ** - Based on the following data about planet X (which orbits ...
- Physics-Gravity - A 17.0-kg satellite has a circular orbit with a period of 2.31...
- Physics - A satellite has a mass of 6146 kg and is in a circular orbit 4.57 × ...

More Related Questions