Zupu
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- Posted: Sun, 14 Jun 2009 04:40:58 +0000
Bai Hikari Tsubasa
Zupu
Bai Hikari Tsubasa
yeah, they actually expect us to draw our own's xD
hn....power output of cara.....
data: car travels along a level road at speed of 25 m s^-1
fuel consumption : 0.2 L km^-1
Calorific value (what in the world is that!?) of the fuel is 5.0*10^6 J L^-1
Engine efficiency 50%
a. at what rate does the engine consume fuel
b. at what rate does the fuel supply energy
c. what is the power output of the engine?
d. How much of the power is used to overcome the frictional forces acting on the car
e. what is the avg frictional force acting on the car
ugh...I hate chain reaction question because it always involve you solving the first one first, and if you can't, you are dead <.<
hn....power output of cara.....
data: car travels along a level road at speed of 25 m s^-1
fuel consumption : 0.2 L km^-1
Calorific value (what in the world is that!?) of the fuel is 5.0*10^6 J L^-1
Engine efficiency 50%
a. at what rate does the engine consume fuel
b. at what rate does the fuel supply energy
c. what is the power output of the engine?
d. How much of the power is used to overcome the frictional forces acting on the car
e. what is the avg frictional force acting on the car
ugh...I hate chain reaction question because it always involve you solving the first one first, and if you can't, you are dead <.<
Ooh, are we finally at heat?
Calorific value should just be how much energy there is in the fuel.
A) so 25m/s = 90km/hr = 0.025km/s... so consumption = 0.2 L/km * 0.025km/s = 0.005L/s.
B) 0.005L/s * 5000kJ/L = 25kJ/s
C) 25kJ/s *50% = 12.5kW
D) .... well... that depends on how much coeff of fric is..... I guess the prob assume the 50% wasted is wasted on fric.... but not necessarily so.
E) ? Coeff of fric?
When you ask me these probs, is it just asking me, or are these probs you dunno how to solve?
c is 50 though .__.
well, those are the questions that I can't solve T^T quite a lot no? although I can still solve half of it xD
hmm.... I don't think it's 50kW... I mean, your fuel only give you 25kW, how do you get more than your fuel gives you?
I see... lol, and I solve them in less than a min, yush, kudos for me!
