China Naming Network - Auspicious day query - Two-speed throttle valve
Two-speed throttle valve
Solution:
A car with a power of P and a mass of M will turn off the throttle when going downhill, and the speed will remain unchanged.
From the kinetic energy theorem, that is, the weight of W at this time -Wf=0
If you don't turn off the throttle, the power will remain the same and the speed will be doubled in t seconds.
Let the initial velocity be v0,
According to the kinetic energy theorem,
Pt+W weight-wf =1/2m (2v0) 2-1/2mv02
It can be concluded from the above two formulas.
v0=√(2Pt/3m)