Chapter 32 : Motion of Vehicles 669
∴ tan α=0·35
0·1443
2·425=or α= 8·2° Ans.
EXERCISE 32.2
- A jeep of mass 1250 kg, with its wheel base of 1·75 m, is going up the plane of inclination
15° with a velocity of 45 km.p.h. If the centre of gravity of the jeep is 1·5 m behind the
front wheel and 80 cm above the ground level, find the distance covered by the jeep to
stop, when the brakes are applied on both the pairs of wheels. Take coefficient of friction
offered by the brakes as 0·6. [Ans. 9·5 m] - An automobile of mass 1500 kg with its base of 2 m is going down a plane inclined at 15°.
If the centre of gravity of the automobile is 1·5 m behind the front wheel and 80 cm above
the ground level, find the distance covered by the automobile to stop, when the brakes are
applied on both the pairs of wheels. Take cofficient of friction of the brakes as 0·6.
[Ans. 24·8 m]
QUESTIONS
- Derive a relation for the acceleration of a vehicle when the tractive force
(a) Passes through its c.g.
(b) Passes through a point other than its c.g. - Explain the difference in the calculations, when a vehicle is driven by both the pair of
wheels, pair of rear wheels and pair of front wheels. - Explain why braking on both the pairs of wheels is considered as a better proposition?
- Discuss the effects of motion of a vehicle, moving upward and downward of an inclined
plane.
OBJECTIVE TYPE QUESTIONS
- The acceleration of a vehicle is maximum when it is driven by
(a) Rear pair of wheels (b) Front pair of wheels
(c) Both pair of wheels. - The term braking distance is used for the distance between the brakes in the front and rear
pairs of wheels
(a) True (b) False - In order to reduce the braking distance of a moving vehicle, we use braking in
(a) Rear pair of wheels (b) Front pair of wheels
(c) Both pairs of wheels. - If the inclination of an inclined plane is increased, then the braking distance of a vehicle
going up the plan
(a) Decreases (b) Remains the same (c) Increases
ANSWERS
- (c) 2. (b) 3. (c) 4. (a)
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