Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

Problem 2 (23 pts): AJackrabbit athlete lays on a bench, where a 100 kg barbell

ID: 1659128 • Letter: P

Question

Problem 2 (23 pts): AJackrabbit athlete lays on a bench, where a 100 kg barbell lys in a rack mere inches in front of their face. Face scru strains against the bar, slowly liting it to the full extension of their arms, 50 em directy above where i started, before bringing it back down again. If the athlete completes this process wasted energy) (k) 30 times over the course of a workout, complete the following (a) Determine the amount of work performed by the at hlete to accomplish this process, assuming ideal performance (le.no (b) If each repetition (each ift) took approximately 2 seconds to go from start (bottom) to full extension (top), what is the athlete's average power output (W).

Explanation / Answer

Solution ) Given mass=100 kg

Height h=50cm=50×10^(-2) m

(a) amount of work performed W=?

We have work done W =mgh (g=10m/s^2)

W=100×10×50×10^(-2)

W=500 Joules

But this process is done 30 times so total work done is W=500×30=15000 Joules

W=15 KJ

In case if net displacement is zero then work done in that case will be zero

(b) average power P =?

We have power = work done/time

( here it is given that it takes 2 seconds for each repetition therefore for 30 repetitions it is 60 seconds so time is taken as 60 seconds)

P=15000/60=250W