# Tractive force exerted by a lorry

1. Aug 20, 2010

### pattricez

Hey would really appreciate help with this question, thx :)

A lorry, of mass 12500kg, starts from rest up a hill. The hill has a gradient of 1:6 and the lorry accelerates at a constant rate of 0.1m/s2. If the resistance to motion, not the gravitational resistance, of the lorry is 2000N, what is the tractive force of the lorry?

thanx again

2. Aug 24, 2010

### john.phillip

This thread should go to the homework section.

Start with a freebody diagram, can you tell all the forces involved ?

How can you relate the given mass and the given resultant acceleration ?

How can you relate self weight, slope effect on weight vector components, motion resistance and the resultant net acceleration ?

3. Aug 24, 2010

### Mech_Engineer

The total tractive force will be the component of the lorry's weight pointing parallel to the incline and the acceleration force. Do you remember how to decompose a vector force into trigonometric components?