1. May 24, 2006

### Natalya18

Hi,
Im studying year 12 physics and im a bit stuck with this question:

The Earth is in its orbit around the sun. The mass of the earth is 6*10^24kg and the radius of its orbit is 1.5*10^11 metres

Question wants me to find the magnitude of the momentum
Im missing something, and i cant seem to remember how to do it,
any help is appreciated,

thanks, :uhh:

2. May 24, 2006

### Curious3141

Start with the formulae for gravitational force and centripetal force.

3. May 24, 2006

### Exotic-Matter

It's a bit simple, as Curious said, start with equating the gravitational and centripetal forces, then substitute in the momentum formula.

4. Jul 12, 2006

### thiotimoline

Need to know the mass of the Sun so that the equation of centripetal force with Sun's gravitational force gives you Earth's orbital velocity, which then can be used to find Earth's momentum.