Comments on: Calculating work done in exercise movements.? http://www.kettlebellreviews.com/kettlebell-workouts/calculating-work-done-in-exercise-movements Reviews of Russian Kettlebells - Where To Buy Kettlebells - Buy Cheap Kettlebells Fri, 10 Sep 2010 12:42:24 +0000 http://wordpress.org/?v=2.7 hourly 1 By: Euler http://www.kettlebellreviews.com/kettlebell-workouts/calculating-work-done-in-exercise-movements/comment-page-1#comment-490 Euler Fri, 05 Jun 2009 00:28:59 +0000 http://www.kettlebellreviews.com/kettlebell-workouts/calculating-work-done-in-exercise-movements#comment-490 The force F of gravity acting on a mass b is F = bg, where g is the acceleration due to gravity, which is g = 9.8 m/s². The work W done by moving an object d meters against a force F is W=dF. So you're right, the work done in moving the ball of mass b through d meters vertically against gravity is W = dbg = 0.3*20*9.8 kg*m²/s² = 58.8 joules. By the way, 1 dietary calorie is 4185 joules, so if you lifted the kettlebell with perfect efficiency through 30cm of height, then you burned 58.8/4185 = 0.014 calories. Of course, the work wasn't done with perfect efficiency.<br><b>References : </b><br> The force F of gravity acting on a mass b is F = bg, where g is the acceleration due to gravity, which is g = 9.8 m/s². The work W done by moving an object d meters against a force F is W=dF.
So you're right, the work done in moving the ball of mass b through d meters vertically against gravity is
W = dbg = 0.3*20*9.8 kg*m²/s²
= 58.8 joules.

By the way, 1 dietary calorie is 4185 joules, so if you lifted the kettlebell with perfect efficiency through 30cm of height, then you burned 58.8/4185 = 0.014 calories. Of course, the work wasn't done with perfect efficiency.
References :

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