Answer:

6000
1.2 J

Explanation:
I = Current = 1 A
t = Time = 2 ms
n = Number of electrocyte
V = Voltage = 100 mV
Charge is given by

The charge flowing through the electrocytes in that amount of time is 
The maximum potential is given by

The number of electrolytes is 6000
Energy is given by

The energy released when the electric eel delivers a shock is 1.2 J
Equivalent capacitance is given by

The equivalent capacitance of all the electrocyte cells in the electric eel is 
The average velocity of Sandy is given by the total distance covered S divided by the total time taken t:

The total distance covered is

while the total time taken is 2 hours + half an hour (for the rest) + 1 hour and half, so

Therefore, the average velocity is
Using the following given values:
Object 1:
Mass = M1 = 2 kg
Velocity before collision = Vb1 = 20 m/s
Velocity after collision = Va1 = -5 m/s
Object 2:
Mass = M2 = 3 kg
Velocity before collision = Vb2 = -10 m/s
Velocity after collision = Va2 = ? m/s<span>
</span>
Obtaining Va2 via law of conservation of momentum:
total momentum after collision = total momentum before collision
M1 * Va1 + M2 * Va2 = M1 * Vb1 + M2 * Vb2
2*-5 + 3Va2 = 2*20 + 3*-10
Va2 = 6.67
Total kinetic energy before collision:
KE1 = (1/2)*M1*Vb1^2 + (1/2)*M2*Vb2^2
<span>KE1 = (1/2)*2*(20)^2 + (1/2)*3*(-10)^2
KE1 = 550 J
</span>Total kinetic energy after collision:
KE2 = (1/2)*M1*Va1^2 + (1/2)*M2*Va2^2
<span>KE2 = (1/2)*2*(-5)^2 + (1/2)*3*(6.67)^2
KE2 = 91.73 J
</span>
Total kinetic energy lost:
Energy lost = KE1 - KE2 = 550 - 91.73 = 458.27 J
Explanation:
The setup contains rock, cylinder, covering lid and atmosphere. One or a few may contribute to the loss of water.
They may be dry, so it might have absorbed water. The rock may be porous and absorb water due to gaps between its molecules.
The material used as lid to cover the cylinder may be not good enogh to stop water from evaporation. The cylinder you might have kept near a hot source and water may have converted water vapor.