Example 5.1. R is the resistance to motion of a train at speed V; find a law of the type, R= a + b 2 connecting R and V, using the following data : V (km/hr): 10 20 30 40 50 q13 R (kg/ton): 8 10 15 21 30 Example 5.1. R is the resistance to motion of a train at speed V; find a law of the type, R= a + b 2 connecting R and V, using the following data : V (km/hr): 10 20 30 40 50 q13 R (kg/ton): 8 10 15 21 30