Exam. 1-B	Automotive Engineering II	1st semester 1428-1429
Student Name:		Student No. 101-      -

 

1- A) Define the following:

a- Coefficient of air resistance (air drag coefficient)- C_d

 

 

b- Car wheel base (b)

 

 

c- Car inertia resistance (IR)

 

 

d- Lateral stiffness (C_a)

 

 

e- Tail wind

 

 

f- Neutral Steer

 

 

2- A) Draw the FBD of a car of mass (m), moving up hell having a slope (θ)^o, if the car has a wheel base (b), and the height of the center of gravity (CG) is (h) m from the ground, and (x) m behind the front axle.

 

 

 

 

 

 

b) Find the weight on the front and rear axles (W_f, W_r), if:

m	1200 kg
θ	10o
b	3.2 m
h	0.6 m
x	1.2 m

 

 

 3- A) A car has mass (m) 1300 kg, and coefficient of rolling resistance (f_r) of 0.018, and a frontal area (A_f) of 2.0 m². If  its drag coefficient (C_d) is 0.5, and the air density (ρ) is 1.2 kg/m³. The car velocity at maximum tractive effort at direct drive is 81 km/h.  Find

a- The rolling resistance of the car (RR)

b- The air resistance of the car (AR), if it is moving against wind (head wind) of 9 km/h

c- The maximum acceleration (a) in this condition if the maximum tractive effort (TE) at that velocity is 1200 N.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

4- Find the inner angle (δ_i) of steering if the outer steering angle (δ_o) is 20^o, for a perfect steering for a car having a wheel base (b) of 3.6 m and a track (t) of 1.8 m.