PLEASSEE HELP MEEE WITHH THESEEE Forty-five cm are equivalent to how many m? State your answer using Scientific Notation.

a
45 x 10^-2 m
b
4.5 x 10^-2 m
c
.45 x 10^-2 m
d
0.45 x10^-2 m
The radius of the earth is 6378 km. What is the diameter of the earth in meters? Use scientific notation to state your answer.

a
6378 x 10^3 m
b
.6378 x 10^3 m
c
6.378 x 10^6 m
d
6.378 x 10^3 m
In an experiment, you find the mass of a cart to be 250 grams. What is the mass of the cart in kilograms?

a
2.5 x 10^3 kg
b
2.50 x 10^3 kg
c
2.50 x 10^-3 kg
d
2.5 x10^-3 kg