Homework 3

Exercise 1:

A) Draw the FBD of a FWD car under acceleration.

 

B) Deduce the equation of maximum acceleration (due to wheel slip) of a front wheel drive car.

 

C) If the car has the following dimensions:

            h = 0.6 m

            x = 1.0 m

            y = 1.4 m

            b = 2.4 m

  Find the maximum acceleration (due to slip) in case of:

            a- Front wheel drive (FWD)

                                                i- m = 0.3

                                                ii- m = 0.8

            b- Rear wheel drive (RWD)

                                                i- m = 0.3

                                                ii- m = 0.8

 

D) Check the results against the Excel program max_ acceleration

Where the input data for the Excel program is as follows:

            m = 1200 kg                                        (T_e)_max  = 180 N.m                   R_w = 0.3 m

            R_f % = y/b = 1.4/2.4 =  0.583              i_g = 3.85

            Rr % = x/b = 1.0/2.4 =  0.417              i_f = 3.27

b = 2.4 m                                             h = 0.9

h = 0.6 m