# Launching a Rocket To mars help

1. May 8, 2009

### Digdug12

1. The problem statement, all variables and given/known data
You are working on a project with NASA to launch a rocket to Mars, with the rocket blasting off from earth when earth and Mars are just aligned along a straight line from the sun. As a first step in doing the calculation, assume circular orbits for both planets. If Mars is now 60.1 degrees ahead of the earth in its orbit around the sun, when should you launch the rocket?

Give your answer in days to the nearest whole number (i.e. 45.6 = 46)

Note: For this problem you need to know the fact that all the planets orbit the sun in the same direction, and the year on Mars is 1.72 earth years.

2. Relevant equations
$$\theta$$(t)=.5$$\alpha$$t2+$$\omega$$ot+$$\theta$$

3. The attempt at a solution
ok so first i used T=2pi/$$\omega$$ to find the $$\omega$$'s of earth and mars using 2pi/T=$$\omega$$,
$$\omega$$e=1.99E-7
$$\omega$$mars=3.43E-7
I also converted the initial position of mars 60.1 degrees into radians, which is 1.049
I then set both position equations of $$\theta$$(t)=.5$$\alpha$$t2+$$\omega$$ot+$$\theta$$ equal to each other and i got
1.049=t(3.43E-7 - 1.99E-7) and then proceeded to take that answer, divide by 60 for minutes, divide by 60 again for hours, and divide by 24 for the number of days.
The correct answer is 146, but i keept getting 84. What am i missing?

EDIT: Nevermind, i found my mistake, thanks anway!

Last edited: May 8, 2009