A weightlifter works out at the gym each day. Part of herroutine is to lie on her back and lift a 41 kg barbell straight upfrom chest height to full arm extension, a distance of 0.55 m .
1. How much work does the weightlifter do to lift the barbellone time?
2. If the weightlifter does 25 repetitions a day, what totalenergy does she expend on lifting, assuming a typical efficiencyfor energy use by the body (25%).
3. How many 430 Calorie donuts can she eat a day to supply thatenergy? Express your answer using two significant figures.
