a) T^e=\(\frac{l_e}{2}\int_{-1}^{1}\)N^T dξ
b) T^e=\(\frac{l_eT}{2}\int_{-1}^{1}\)N^T dξ
c) T^e=\(\frac{l_eT}{2}\int_{-1}^{1}\)N^T
d) Undefined

Answer: b
Explanation: The term traction force can either refer to the total traction a vehicle exerts on a surface or the amount of total traction that is parallel to the direction of motion.
Element traction force is given by
T^e=\(\frac{l_eT}{2}\int_{-1}^{1}\)N^T dξ