Answer:
a. water
Explanation:
A buoy is a floating object that is used in the sea to locate some point or as a checkpoint. It stays at its designated position in the sea by means of an anchor chain. This chain is made short in length according to the water depth do the buoy can not deviate much from its position. The same mechanism can be applied to the metal ion. When a metal ion is formed it remains at its place, but the electrons are mobile and they travel when they get a medium. For example in circuits or from one atom to other. And for the case of buoy, the water serves as electrons as the water is moving in the medium. Hence, the second analogy will be:
electrons : water
So, the correct option is:
<u>a. water</u>
The calculation for kinetic energy is this
KE = 1/2mv^2
KE = 1/2(50)(7^2)
KE = 1/2(49•50)
KE = 1225 kgm^2/s^2.
Or simply 1225 J.
She possess this much energy when she runs.
Answer: 
Explanation:
Given
Charge discharged 
time taken 
Current is given as rate of change of discharge i.e.

Therefore, the average current is 
The heat required to change 1.25 kg of steak is 2825 kJ /kg.
<u>Explanation</u>:
Given, mass m = 1.25 kg, Temperature t = 100 degree celsius
To calculate the heat required,
Q = m
L
where m represents the mass in kg,
L represents the heat of vaporization.
When a material in the liquid state is given energy, it changes its phase from liquid to vapor and the energy absorbed in this process is called heat of the vaporization. The heat of vaporization of the water is about 2260 kJ/kg.
Q = 1.25
2260
Q = 2825 kJ /kg.