Question

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

Answer 1

Q1: (a)

`1cm \: = 10 {}^( - 2)m`

so

`45 * {10}^( - 2) m`

Q2:

`1km = 10 {}^(3) m \\ 6378km * {10}^( 3)`

this is the radius in meter

diameter = 2r

in this i don't know which choice is the right answer

Q3:

`1gram = \: {10}^( - 3) kg`

so

`250 * {10}^( - 3) = 2.5 * {10}^( - 1) kg`

again there is no correct answer