Question

A vehicle of 1 200 kg is moving at a speed of 40 km/h on an incline of 1 in 50. The total constant rolling and wind resistance is 600 N. The efficiency of the drive from the engine trough the gearbox to the wheels is 80 % and the gear ratio causes a final engine to wheel velocity ratio of 4:1. The effective wheel diameter is 500 mm. Calculate the engine power to maintain this speed.

Answer 1

Answer:11.602 KW

Explanation:

mass of vehicle$\left ( m\right )=1200 kg$

speed=40Km/h

Resistance=600 N

$\eta =80%$

Gear ratio$\left ( G\right )=4:1$

$D_{effective}=500mm$

Net force to overcome by engine is

F=Resistance + sin component of weight

F=600+$mgsin\theta$

Where $tan\theta =[tex]\frac{1}{50}$

$\theta =1.1457^{\circ}$

$F=600+1200\times 9.81\times sin\left ( 1.1457\right )$

F=600+235.38=835.38 N

power=$F.v=835.38\frac{100}{9}$

Engine Power=$\frac{835.\frac{100}{9}}{\eta }$=11.602 KW