Recent content by gen x

Car acceleration decrease when speed rise (even if aero/tire drag is zero), because thrust force decrease. Torque at wheels are smaller and smaller as you shift gears, gear ratios become lower each shift

When I run is harder, but when I run I use more power , my leg rpm is higher and my force push on each stair is higher.

In case of bike, lets say my foot push on pedals only in half circle, when I am above pedal so my weight ( mg) make force on pedals. How my force on pedals decrease with speed if mg is constant?

When I decrease F and use higer gears ratio, I can incease my speeed, but my power still remain the same. Is my example with horse counter intuitive to you as well or not?

Imagine if car travel in different medium so at 100km/ and 200km/h is same drag force at car. It turns out that car that travel at 200km/h need more power only because it travel at faster speed, even medium drag is the same, isn't that wierd? That show me, my physics/life intuition is totally...

Power = Force v Speed Power of my horse = 104kgx9.81m/s^2 x 0.732m/s = 1HP =746W Force/tension in rope stay the same if horse run at 0.73m/s or at 15m/s, so why then horse need to be more powerfull to pull at higher speed even if backward force at him(rope tension) stay the same? I understand...

You mean point where cruves from lower and higher gear intercept? yes here torque at wheel are the same

Torque at wheel is smaller in 4th gear then in 3rd gear, acceleration is smaller in 4th gear compare to 3rd gear.

In one gear (ex. in 3rd gear), max torque on wheel(max thrust=max acceleration) is not at engine max power, it is on engine max torque. The highest instantaneous acceleration will be in 1st gear at max engine torque. I can't find these graphs.

Yes manfacturer do that based on some calculation, they do this to get max acceleration. But if they add few more gears and make them shorter, then can engine be more often close to peak power rpm. Shifting time today can be only 40miliseconds, so shifting is not a problem. Has high revs...

Optimal rpm window is "power band" or "rpm power window" that engine use for max acceleration. you can see this engine operate in rpm power window from 6500-9000rpm, as he shift in higher gears, rpm window become narrower. @jbriggs444 If we have two engines with same peak power, but...

Yes that is instatenuos acceleration for that specific rpm, but power and torque change in my operating rpm window, so called "power band". There is two goal of my question. 1. Learn how to comparing acceleration/"performance" of two power/torque curves at their optimal rpm window. 2. Find...

Thanks. I choose random photo from net. We can look at this, just assume both have same max power. Is there any advantge for engine that revs higher? NA engine turbo engine

Let say we want find out acceleration of two cars with same max power, comparing only power/torque graphs, both cars are 100% identical, same mass, aero drag,etc so difference is only in rpm and power/torque curve. Cars dont use CVT gearbox(allows to keep engine at max power) they both use...