When a client performs an exercise they move the 50 lb barbell 1.5 ft during each repetition. How much work have they performed if they do 4 sets of 6 repetitions?
a. 1800 lb. ft.
b. 450 lb. ft.
c. 1200 lb. ft.
d. 1500 lb. ft.
e. 75 lb. ft.
Answer: a. 1800 lb. ft.