Question1
A person doing a chin-up weighs 725 N, disregarding the weight of the arms. Throughout the first 20.0 cm of the lift, each arm exerts an upward force of 371 N on the torso. If the upward movement starts from rest, what is the person's speed at this point?
Question2
The least possible note on a grand piano has a frequency of 27.5 {rm Hz}. The entire string is 2.00 {rm m} long and has a mass of 400 {rm g}. The vibrating section of the string is 1.90 {rm m} long. What tension is necessary to tune this string properly?