Recent content by johnpauldisec

  1. johnpauldisec

    Calculating acceleration on different gears in vehicle

    But its not so simple. Take in mind i can change torque to anything i want using gears. I could apply a gearing that would make from 100 Nm of torque at engine a 50000 Nm of torque at wheels. That can't mean i could accelerate fast as hell, there is no free energy But what is "distance covered...
  2. johnpauldisec

    Calculating acceleration on different gears in vehicle

    Yes, but clutch is for combustion engines. When they stall they don't generate any torque and they need electric starters to accelerate revs until it rotates on its own. If you have electrical engine you don't need a clutch, even had a radio controlled toy? Or have you ride bicycle? when its...
  3. johnpauldisec

    Calculating acceleration on different gears in vehicle

    Ok, but then how the car will start moving when its stalled and engine is stalled? if power is 0 at 0 rpm.
  4. johnpauldisec

    Calculating acceleration on different gears in vehicle

    Really? then what if my car and engine is stopped. And now i apply electric power to motor. This motor can generate torque at 0 rpm. So there is also force on wheel. But the power is 0 because rpm is 0.
  5. johnpauldisec

    Calculating acceleration on different gears in vehicle

    The engine is electrical and its maximum torque is at 0 rpm, on bigger rpm it has lower torque so power remains constant. Full power is on any rpm on that engine. And seems we misunderstood. In my car i was driving full power at 3rd gear and switched to a fifth gear. Vehicle speed was same...
  6. johnpauldisec

    Calculating acceleration on different gears in vehicle

    @willem2 if you read my full post: this engine's power is constant 50HP no matter revolutions
  7. johnpauldisec

    Calculating acceleration on different gears in vehicle

    But i don't want to have 0 rpm of engine at bike 2 m/s speed. I want to have my bike stopped and engine stopped. Now i apply electrical power to engine so it starts generating torque at 0rpm. What force will be applied on wheels/on bike? Will it start to move? If i use your calculations the bike...
  8. johnpauldisec

    Calculating acceleration on different gears in vehicle

    I agree that best power and ACCELERATION will be at 300 rpm. But you can't equal force with power. In your posted forces, at 0 rpm force is 0. So the car/bike would NEVER START MOVING. Which is not true. Also, look: imagine a sports car that has peak 400HP at 6000 rpm. I put first gear...
  9. johnpauldisec

    Calculating acceleration on different gears in vehicle

    The force on wheels is torque on wheel divided by wheel radius Don't even try to suggest that car on higher gears generate same force on wheels (assuming same engine rpm and power is present). The higher gear the less force -> its very easy to wheel spin at first gear if you press pedal to...
  10. johnpauldisec

    Calculating acceleration on different gears in vehicle

    Look at this picture its from https://en.wikipedia.org/wiki/Mechanical_advantage_device article compare first and fourth pulley the fourth have only 25N applied but its generating same force and acceleration as 100N in first pulley I KNOW WORK and energy are same but the fact is first...
  11. johnpauldisec

    Calculating acceleration on different gears in vehicle

    @meBigGuy force times distance? the distance is wheel diameter, WHAT if i use same wheel size but i attach differential/gear to my engine speed torque engine_rpm wheel_rpm vehicle A 10 100 200 50 vehicle B 20 100 400...
  12. johnpauldisec

    Calculating acceleration on different gears in vehicle

    Acceleration is not Force/mass, mechanical advantage (?) I have a vehicle with wheels and electric motor that drives that wheels. Those are characteristics of engine Resultant torque and velocity at wheel will depend on radius of that wheel, as wheel work as gearing. Let's say i will try...
  13. johnpauldisec

    Calculating mutiple forces on a body

    Hi I am making physics engine (computer) and i have some problems with interpretating multiple forces on one body. http://img837.imageshack.us/img837/396/75i7i47i6.png On the fourth car (on right) there are two forces acting on two rear wheels, interpretation is obvious, but what when...
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