Whoa!

A weightlifter bench presses 80kg (approx. 175lbs.) 0.75m straight up.

a.

How much work does she do, assuming constant velocity, in one lift (just the 0.75m straight up)?

b.

How many repetitions would she have to do to burn off 1 Hamburger (400 Calories)(1 Calorie = 4.186J) (remember the motion going down as well!)

Note:

This is not going to be an accurate representation of how much work you need to do to burn off 400Cal. It is just an indicator for how much energy is stored in food, not all of which is recoverable, and how little energy it takes to do physical work.

• Hint:
• Solution:part a.
• Solution:part b.