* A lumen is the same as Lux and is what many modern light meters will calculate their measurement in. The next step is to calculate the number of watts. One lumen is = 0.001496 watts. This is pretty simple, after you have your total number of lumens from step 2.
Quick Answer. The formula for speed is s = d/t, where s equals the speed, d is the distance covered and t is the time it took to cover the distance. The formula for finding the instantaneous speed at a specific point is found by taking the derivative of the speed equation. Continue Reading.
For vector calculus, it is the magnitude of the velocity. Definition of Speed. Let r(t) be a differentiable vector valued function representing the position of a particle. Then the speed of the particle is the magnitude of the velocity vector. Find the speed after p/4 seconds. In one variable calculus, we defined the acceleration of a particle as the second derivative of the position function.