Question

Express the speed of light in metres per pico second ( c = 3 × 10⁸ ms^-1.)

Answer 1

1. A picosecond is a unit of time formed by the prefix pico- and the SI unit second, equal to 10⁻¹² or $\frac{1}{1000000000000}$of a second.
2. 1 picosecond = 10^-12 second = $\frac{1}{1000000000000}$second
3. 1 sec = 10¹² picosecond
4. Given, c = 3 × 10⁸ ms^-1.

= 3 × 10⁸$\frac{m}{sec}$

= $\frac{3\times {10}^{8}m}{{10}^{12}picosecond}$

= 3 × 10⁸ × 10^-12 m/pico second

= 3 × 10^-4 m/pico second.

Hence, the speed of light in meters per picosecond is 3 × 10^-4 m/pico second.