1.The weight lifter is bench-pressing a barbell whose weight is 710 N. Then raises the barbell with a distance of 0.65 m above his chest, and then he lowers it with the same distance. The weight is raised and lowered at a constant velocity. Determine the work done on the barbell by the weight lifter during (a) the lifting phase and (b) the lowering phase.
Solved 1 Answer
See More Answers for FREE
Enhance your learning with StudyX
Receive support from our dedicated community users and experts
See up to 20 answers per week for free
Experience reliable customer service
Step 1weight = 710N distance = 0.65 m a)work done during lifting phase = weight * displacement * cos(0o) = 710* 0.65*1 = 461.5 Joules Step 2work done during lowering phase = weight * distanec * cos(180o) = - 710 * 0.65  = -461.5 Joules  ...