Quote:
Originally Posted by ahausheer
So basically Hp is an enabler of torque? Torque moves you forward and hp determines how long that torque can be applied. Off topic I know. Ill discuss elsewhere.
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It's more on-topic here than the usual threads that power vs torque comes up in. Power -more or less- tells you how quickly you can apply a torque.
Think of a bicycle. You apply a force to the pedal, which turns the crank. That force is applied to the chain, but can also be measured in terms of torque (rotating force) around the bottom bracket.
You can push a pedal hard when it's stopped or rotating slowly. The limit of how hard you can push on the pedal is akin to an engine's torque rating.
How fast you rotate the pedal is akin to an engine's speed.
If you downshift, it takes less force to push the pedal, but now you can pedal faster. The combination of how much force you apply and how quickly you pedal is akin to an engine's power.
If you downshift so that you're pushing half as hard but rotating twice as quickly, you'll deliver the same amount of power and accelerate the same. But if you downshift and can deliver the same force to the pedal twice as quickly, you'll have twice the wheel torque. Even if you push with 25% less force, but pedal twice as fast, you'll accelerate more than before the downshift.
Just like in a car: if you downshift so that you make more power, you make more wheel torque and accelerate more (even if you make less engine torque after the downshift).
It's not a perfect metaphor, but the principle is the same.
Quote:
Originally Posted by bambbrose
If you are going to correct us on on a nuance, at least get it right. What you feel technically comes from the seat pushing you forward. Draw a free body diagram of your body when accelerating  |
I'll see your FBD comment and raise.
What I posted is correct: what you feel *comes from* the force at the wheels (there's a reason I didn't write that what you feel *is* the force of the wheels). I originally drafted
"What you feel is the seat pushing you, which comes from force at the wheels, which comes from wheel torque." but I decided it was unnecessarily wordy and too douchy to put it that way, so I trimmed it.
Besides, my post wasn't nuanced. This is nuanced: what you feel (unless you drive around topless) is your shirt pushing on you, which comes from the forces transfered from the tires to the wheels through the car to your seat to your clothes to you.
Quote:
Originally Posted by bambbrose
If a balloon is floating in a car, and the car accelerates, does the balloon go backwards from the acceleration?? This was a junior level physics problem for my mechanics class  |
So that's not covered until junior year now? Back in my day, we did that one as a freshman.
I'll let someone else answer. Since we're off-topic anyway, here's some extra credit: Explain the differences, if any, for how it works for balloons filled with helium vs air.