A light year is defined as the distance that light can travel in one year. It is measured to be $9460730000000000$9460730000000000 metres.
Write this using scientific notation.
How many kilometres is this? Write this using scientific notation.
How many centimetres is this? Write this using scientific notation.
Light can travel at a speed of $300000000$300000000 m/s.
A micrometre (µm) is defined as being a millionth of a metre. This means that $1$1 µm is $0.000001$0.000001 m.
The size of a fog, mist or cloud water droplet is approximately $10$10 µm. How many would fit in a $9$9 cm sample?
Round your answer to the nearest whole unit.
A nanometre (nm) is defined as being a billionth of a metre. This means that $1$1 nm is 0.000000001 m.
The germ has an approximate size of $1000$1000 nm. How many would fit in a $9$9 cm sample?