# Power and torque for the bus

1. Jun 6, 2009

### yanikomer

1. The problem statement, all variables and given/known data
i want to find the required engine for a bus.
it is 15000 kg with passengers
12 metre length
i want to find starting torque and power required when it is on an inclined plane(%15)
and also i want o calculate the torque and the power of the engine required when it is going on a level road with 70 km/h

2. Relevant equations

i am looking for the equations that i can find the solution

3. The attempt at a solution

thank you

2. Jun 7, 2009

### Naty1

Maybe you need to know: HP = (torque (ft lbs)) x rpm)/5252 and a HP is 550 ft-lb/sec

On the inclined plane, you'll want to find the component of the 15,000 lb bus weight along the incline...however, from a practical point of view there really isn't enough information to answer your questions...you need an assumption about friction forces....the length of the bus is irrelevant...

If the weight component was say 5,500 lbs along the incline and you were satisfied with an abysmally slow, unrealistic acceleration, 5500/550 or 10HP would just get it moving neglecting all frictional forces.

On a level raod, you'd need to know the rolling resistance with the road plus the wind resistance against the bus.

3. Jun 10, 2009

### yanikomer

for unknown values i will make assumption but i need only the formulas.
how can i calculate the required torque and power of the engine to move the bus on an inclined plane?

4. Jun 22, 2009

### yanikomer

i want to find the required torque and power while starting to move the bus on an inclined plane. do you know which words i can use while searching it on web ?