The speed of light is 3×108 m/s3 \times 10^8 \text{ m/s}3×108 m/s. How many kilometers per microsecond\text{kilometers per microsecond}kilometers per microsecond is this?
0.3 km/\mus0.3 \text{ km/\mu s}0.3 km/\mus
300 km/\mus300 \text{ km/\mu s}300 km/\mus
3 km/\mus3 \text{ km/\mu s}3 km/\mus
0.0003 km/\mus0.0003 \text{ km/\mu s}0.0003 km/\mus