Answer:
m = 20,000 kg
Explanation:
Force, 
Acceleration of the shark, 
It is required to find the mass of the shark. Let m is the mass. Using second law of motion to find it as follows :
F = ma
Putting the value of F and a to find m

So, the shark's mass is 20,000 kg.
Potential Energy (Initial one) = m * g * h
P.E. = 60 * 9.8 * 10
P.E. = 5880
Kinetic Energy (Final One) = 1/2 mv²
K.E. = 1/2 * 60 * (10)²
K.E. = 6000/2
K.E. = 3000
Lost Energy = 5880 - 3000 = 2880 J
In short, Your Answer would be 2880 Joules
Hope this helps!
Answer:
If the starting GPE is doubled than it's KE would also double.
I think phosphorus has the highest density at room temp.