Consider the following situation: A bungee jumper, mass = 50 kg, falls backwards
ID: 1415164 • Letter: C
Question
Consider the following situation: A bungee jumper, mass = 50 kg, falls backwards from a high bridge. Suppose the bungee cord behaves just like a spring with a spring constant of 50 N/m. Answer the following questions, assume there is no air resistance. Is the energy of the bungee jumper conserved in this problem? Explain your reasoning. What is the speed of the bungee jumper when she is 10 m below her starting location? What is the farthest distance below the bridge the bungee jumper gets? How does the lowest point the bungee jumper gets to with air resistance compare the the lowest point without? Explain your reasoning in detail.Explanation / Answer
(a)
Yes Energy is conserved , duie to Law of conservation of Energy !!
(b)
Using Energy Conservation,
Potential Energy = Spring Potential Energy + Kinetic Energy
m*g*h = 1/2*kx^2 + 1/2*m*v^2
50 * 9.8 * 10 = 1/2 * 50 * 10^2 + 1/2 * 50 * v^2
v = 9.8 m/s
(c)
At farthest distance, v = 0
So,
Using Energy Conservation,
Potential Energy = Spring Potential Energy + Kinetic Energy
m*g*h = 1/2*kx^2 + 1/2*m*v^2
50 * 9.8 * x = 1/2 * 50 * x^2 + 0
x = 19.6 m
(d)
With air Resistance, Lowest point is a bit high as compared to without air Resistance.
Reason being some of the energy will be wasted in air resistance !!