Find the correct value:
 
An 9000 \(kg\) engine pulls a train of 4 \(wagons\), each of 2500 \(kg\), along a horizontal track. If the engine exerts a force of 60000 \(N\) and the track offers a friction force of 4000 \(N\), then calculate:
 
a. the net accelerating force and
 
b. the acceleration of the train
 
a. Net accelerating force \(=\)  \(N\)
 
b. Acceleration of the train \(=\)  ms2
 
[Note: Enter your answers with two decimal digits.]