Question

2. A 60 kg diver jumps off a diving board with a height of 10

meters and accelerates toward the ground. At the point shown
in the diagram, she has 1,764 Joules of gravitational energy
and 4,116 Joules of kinetic energy. What is the diver's total
mechanical energy at that point?
A. 1,764 Joules
B. 2,352 Joules
C. 4,116 Joules
D. 5,880 Joules
10 m
PE = 1,764)
KE = 4,116)
Om

Answer 1

D. 5880 Joules

Step-by-step explanation:

When the diver is at the highest point it has the maximum potential energy and his kinetic energy is zero due to zero velocity. As the diver jumps and accelerates during the downward motion his kinetic energy increases with the increase in speed. While the gravitational potential energy of the diver decreases due to a decrease in the height of the diver. According to the law of conservation of energy the potential energy of the diver is being converted into its kinetic energy during the downward motion. But the total mechanical energy of the diver remains constant which is equal to the sum of gravitational energy and the kinetic energy of the diver at any point.

`Mechanical\ Energy = Kinetic\ Energy + Gravitational\ Energy\\Mechanical\ Energy = 4116\ J + 1764\ J\\Mechanical\ Energy = 5880\ J`

Therefore the correct option is:

D. 5880 Joules