**A100 -- Dan Swearingen **

**Math Practice Homework - Points earned on this assignment will be
applied towards any points lost on the In Class math quiz. Due Tuesday,
September 24 at the beginning of class.**

**Numerical Problems**:

Show all work.

Do all work on your own paper.

All answers must be in proper scientific notation: "n.mmm... x
10^{p}".

**Evaluate the following **

1. 10^{6} x 10^{2} =

2. 10^{11}/10^{4} =

3. (4 x 10^{-6})/(8 x 10^{-4}) =

4. 1/(100 x 10^{55} x 10^{-16} x 10 x 10^{82})
=

5. 2 x 10^{-5} - 4 x 10^{-7} =

6. 3 x 10^{27} + 5 x 10^{28} =

7. 2 x 10^{-125} x 5 x 10^{122}
=

8. (10 x 2 x 10^{-4} ) / (3 x 10^{2}
x 4 x 10^{2} ) =

9. (7.5 x 10^{-9}) / (3 x 10^{-9})
=

10. (2 x 10^{2A} x 6 x 10^{-2L}
) / (3 x 10^{12A} x 7 x 10^{4L}
) =

11. 10^{18} + (3 x 10^{21})
+ (7 x 10^{24}) =

**For the following problems, solve for the variable
indicated. **

12. If:
what is *m*_{1} = ?

13. If:what
is *M _{wd }*?

14. If: what
is *M _{wd}* ?

**Perform the following calculations:**

The escape velocity *v _{esc}* and the thermal velocity

**Calculate v_{esc} and v_{Thermal}.
**

Where:

*G* = 6.7 x 10^{-11} [m^{3} kg^{-1} sec^{-2}
]

*M* = Mass of Earth = 5.9742 x 10^{27} kg

*R* = Radius of Earth = 6,378.14 km

*k* = 1.38 x 10^{-23} [J/^{o}K]

*m _{gas}* = mass of four protons = 4 x 1.67 x 10

T = room temperature in Kelvin which is about 300^{o} K

Note: make sure units are consistent. Answers should be *velocities*
(a.k.a. speed) so final units should be in meters per second.