Express the following numbers in scientific notation:
(i) \( 2000000 \)
\[2000000 = 2.0 \times 10^6\]
(ii) \( 48900 \)
\[48900 = 4.89 \times 10^4\]
(iii) \( 0.0042 \)
\[0.0042 = 4.2 \times 10^{-3}\]
(iv) \( 0.0000009 \)
\[0.0000009 = 9.0 \times 10^{-7}\]
(v) \( 73 \times 10^3 \)
\[73 \times 10^3 = 7.3 \times 10^4\]
(vi) \( 0.65 \times 10^2 \)
\[0.65 \times 10^2 = 6.5 \times 10^1\]
2. Express the following numbers in ordinary notation:
(i) \( 8.04 \times 10^2 \)
\[8.04 \times 10^2 = 804\]
(ii) \( 3 \times 10^5 \)
\[3 \times 10^5 = 300000\]
(iii) \( 1.5 \times 10^{-2} \)
\[1.5 \times 10^{-2} = 0.015\]
(iv) \( 1.77 \times 10^7 \)
\[1.77 \times 10^7 = 17700000\]
(v) \( 5.5 \times 10^{-6} \)
\[5.5 \times 10^{-6} = 0.0000055\]
(vi) \( 4 \times 10^{-5} \)
\[4 \times 10^{-5} = 0.00004\]
3. The speed of light is approximately \( 3 \times 10^8 \) metres per second. Express it in standard form.
\[\text{Answer: } 300000000 \, \text{metres per second}\]
4. The circumference of the Earth at the equator is about \( 40075000 \) metres. Express this number in scientific notation.
\[40075000 = 4.0075 \times 10^7\]
5. The diameter of Mars is \( 6.7779 \times 10^3 \) km. Express this number in standard form.
\[6.7779 \times 10^3 = 6777.9 \, \text{km}\]
6. The diameter of Earth is about \( 1.2756 \times 10^4 \) km. Express this number in standard form.
\[1.2756 \times 10^4 = 12756 \, \text{km}\]
