Question

Jessica is visiting a park with her mother. Jessica sits on a swing. Her mother pulls the swing to a height of 3 meters above the ground and lets it go. The image shows Jessica at three positions on the swing. Jessica‘s mass is 44 kilograms and the maximum velocity of the swing is 5 meters/second. What’s the energy she has at each position shown? Ignore friction and air resistance. Use g = 9.8 m/s2, PE = m × g × h, and KE= 1/2 mv^2

Answer 1

You are given Jessica's height of the swing 3 meters above the ground, velocity at 5m/s²  and her mass of 44 kilograms. Since there is no image given, I will assume that the position at maximum and minimum height, that is 3 and 0 meters.

Position at maximum height
PE = mgh
PE = 44kg *9.8m/s²*3
PE = 1,294 J

Position at minimum height
PE = 0 J

Position at maximum velocity
KE = 1/2*mv²
KE = 1/2*44kg*(5m/s²)²
KE = 550 J

Position at minimum velocity
KE = 0 J