分析:本题根据不同物理量单位的进率进行换算.换算的步骤为:原来的数字、乘号、进率、后来的单位、最终结果.
解答:解:
①∵1m/s=3.6km/h,∴10m/s=10×3.6km/h=36km/h;
②∵1nm=10-9m,∴12nm=12×10-9m=1.2×10-8m;
③∵1h=3600s,1min=60s,∴2h15min=2×3600s+15×60s=7800s.
故答案为:36;1.2×10-8m;7800.
点评:单位换算时注意“先换后算”,例如:45m=45×1000mm=45000mm.