Hello! I had a question about this graph:
I think that power = (torque)(angular velocity), correct me if I’m wrong. But it doesn’t seem to match this graph.
For example, 60% of 100 rpm is 60 rpm, which is 1 rps. Multiplying this by 2 newton-meters you get 2 watts. But the graph shows 13 watts. What am I doing wrong?
For your math to work, you need to express the angular velocity in radians per second. 1rps is 6.28rad/s.
It’s also perfectly logical, there is nothing special about rotational power. It’s still good ole
E[J] = F[N] * s[m] (energy is force times distance)
or, for power
P[W] = F[N] * v[m/s] (power is force times velocity)
Now torque is “force applied at the end of an arm”. This end of arm runs a circular path, so for distance(or velocity), you need to consider the circumference of said path, 2 * π * r. The angular velocity w is 2πf [rad/s], the linear velocity of an endpoint of a hypothetical 1m arm at 1rps is ~6.28m/s and at 2Nm, the equivalent force on that endpoint is 2N.
2N * 6.28M/s = 12.56W
