A camera drone must complete a 900 m survey route with an average speed of 6.0 m/s. It covers the first 300 m in 30 s and begins the remaining part immediately at a constant speed.
What is the constant speed needed for the remaining part of the route?
6.0 m/s6.0\ \mathrm{m/s}6.0 m/s
2.0 m/s2.0\ \mathrm{m/s}2.0 m/s
4.0 m/s4.0\ \mathrm{m/s}4.0 m/s
5.0 m/s5.0\ \mathrm{m/s}5.0 m/s