Posted by **Me** on Tuesday, November 29, 2011 at 11:45pm.

While visiting Planet Physics, you toss a rock straight up at 13.6 m/s and catch it 3.50 s later. While you visit the surface, your cruise ship orbits at an altitude equal to the planet's radius every 340.0 minutes.

What is the mass (in kg) of the planet?

- Physics help please -
**drwls**, Wednesday, November 30, 2011 at 10:40am
The time of flight of the tossed rock is T = 2 Vo/g = 3.50 s.

Therefore the local value of g is

2 Vo/T = 7.77 m/s^2

The value of g is related to the radius R and mass M of the planet by

g = G*M/R^2

From the period of the orbit, you know that the orbital velocity is

V = 2*pi*R/P

where P is the known period, 20,400 s.

Since m V^2/R = m g,

4*pi^2*R/P^2 = 7.77 m/s^2

That equation can be solved for the orbit radius, R.

Then use g = G*M/R^2 for M

G is the universal constant of gravity,

6.67*10^-11 N m^2/kg^2

## Answer this Question

## Related Questions

- Physics help please! - While visiting Planet Physics, you toss a rock straight ...
- Physics help please! - While visiting Planet Physics, you toss a rock straight ...
- Physics please help - While visiting Planet Physics, you toss a rock straight up...
- Physics Find mass and radius of planet. - While visiting Planet Physics, you ...
- Physics - While visiting Planet Physics, you toss a rock straight up at 15 and ...
- Physics help ASAP - Suppose you are visiting a planet in a distant part of the ...
- Physics - The acceleration of gravity at the surface of a newly discovered ...
- physics - A person going for a morning jog on the deck of a cruise ship is ...
- Physics help please - You are the science officer on a visit to a distant solar ...
- Math - A surface ship is moving in a straight line (horizontally) at 8km/hr. At ...