What Is the Realistic Horsepower of a Truck Climbing Rabbit Ears Pass?

  • Thread starter Thread starter pippintook
  • Start date Start date
  • Tags Tags
    Horsepower Truck
Click For Summary
SUMMARY

The discussion focuses on calculating the horsepower required for a 40,000 kg truck to climb Rabbit Ears Pass, which has an elevation change of 6,560 feet. The initial calculation yielded an unrealistic value of 57,442 horsepower, prompting a reevaluation of the units and approach. The correct method emphasizes the importance of using consistent units, specifically converting measurements to meters, seconds, and kilograms. The key takeaway is that only the vertical speed should be considered for accurate horsepower calculations.

PREREQUISITES
  • Understanding of basic physics concepts, particularly work and power
  • Familiarity with unit conversions, especially between imperial and metric systems
  • Knowledge of gravitational force and its impact on mass
  • Ability to apply formulas for calculating horsepower in mechanical systems
NEXT STEPS
  • Research the formula for calculating work done against gravity in physics
  • Learn about unit conversion techniques, focusing on feet to meters and minutes to seconds
  • Explore the concept of vertical speed and its relevance in horsepower calculations
  • Investigate real-world examples of horsepower requirements for heavy vehicles on inclines
USEFUL FOR

This discussion is beneficial for mechanical engineers, physics students, and automotive enthusiasts interested in understanding the power requirements for trucks climbing steep elevations.

pippintook
Messages
17
Reaction score
0
A 40,000 kg truck traveling on I-70 leaves Denver (elevation 5280', mile marker 244) and goes over Rabbit Ears pass (elevation 11,840', mile marker 238) while maintaining 50 mph. What is the horse power rating on his engine?


The formulas I used are as follows:

power = work/time

work = (mass)(gravity)(height)

746 watts = 1 horsepower

To solve for time I did 50 miles/60 minutes = 6 miles/x minutes and got 7.2 minutes (or 432 seconds).

After putting in all of these numbers I got 57,442 horsepower. This doesn't seem to make sense though, as that is a LOT of horsepower. I think the problem may be the height, since I put in the change of height (6560 feet). Help please? Suggestions?
 
Physics news on Phys.org
Put everything into metres, seconds and kg, I suspect you have got the units mixed up.

Hint - you only care about the vertical speed.
 

Similar threads

History What is the history of my old Chevy truck?
  • · Replies 26 ·
Replies
26
Views
5K
Why is the U-2 nicknamed the Dragon Lady?
  • · Replies 4 ·
Replies
4
Views
9K