f. 2-3 approximation help.

1. Light travles at 299792.5 km/s. Thedistance between the Sun and the Earth is 149597890 km. Estimate the approximate time ( in seconds) required by light to travel from the Sun to the Earth.

149597890 / 299792.5 = 499 seconds
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3. Express the following numbers in scientific notation.


a) 12345.6789 = 1.23456789 * 10^ - 4


b) 1230000000 = 1.23 * 10^9



c) 0.00987 = 9.87 * 10^3
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1. Express the following fractions as decimals and correct your answers to 3 significant figures.


a) 3 / 7 = 0.4285... = 0.429(3 sig.)


b) 8 / 130 = 0.06153... = 0.0615(3 sig.)
2. Calculate the following and give your answers correct to 4 significant figures.


a) 2.34 x 5.1 / 4.23 = 2.8212... = 2.821(4 sig.)


b) 1.89 + 0.57 x 3.4 - 2.21 / 56 = 3.7885...= 3.789(4 sig.)
3. Express the following quantities using the units specified in the brackets and correct your answrs 2 decimal places.


a) 43209g (kg)__= 43209 / 1000 = 43.209 = 43.21kg(2 dec.)___________


b) 21s (h)___= 21 / 3600 = 0.005833... = 0.01 h(2 dec.)___________