Calculate the mean piston speed, bmep, and specific power of: (a) the spark-ignition engines in Figs. 1.11 and 1.13 at their maximum rated power and torque; and (b) the mean piston speed, bmep, and specific power of the diesel engines in Figs. 1.31 and 1.32 at their maximum rated power and torque. Briefly explain any significant differences between these two types of engine.

  answer:

  write 548 as 500 + 40 + 8. multiply each addend by 5. then add the three products to get 2,740.

7.9m and 4.3°

step-by-step explanation:

let east be +x and north be +y, x = distance * cos θ, y = distance * sin θ  

for 3.5 south, y = -3.5  

for 8.2, x = 8.2 * cos 30 and y = 8.2 * sin 30  

for 15 west, x = -15  

total x = 8.2 * cos 30 – 15 ≈ -7.9  

total y = -3.5 + 8.2 * sin 30 = 0.6  

magnitude = [(8.2 * cos 30 – 15)^2 + 0.6^2)]^0.5  

the magnitude is approximately 7.9 m  

tan θ = y/x = 0.6/-7.9  

the angle is approximately 4.3˚ north of west