Answer:
The discharge rate is 
Explanation:
From the question we are told that
The diameter is 
The head is 
The coefficient of contraction is 
The coefficient of velocity is 
The radius is mathematically evaluated as

substituting values


The area is mathematically represented as

substituting values


The discharge rate is mathematically represented as

substituting values


(A) We can solve the problem by using Ohm's law, which states:

where
V is the potential difference across the electrical device
I is the current through the device
R is its resistance
For the heater coil in the problem, we know

and

, therefore we can rearrange Ohm's law to find the current through the device:

(B) The resistance of a conductive wire depends on three factors. In fact, it is given by:

where

is the resistivity of the material of the wire
L is the length of the wire
A is the cross-sectional area of the wire
Basically, we see that the longer the wire, the larger its resistance; and the larger the section of the wire, the smaller its resistance.
Density is defined as [mass] / [volume] .
The only choice listed with those physical dimensions is 'd' .
Answer:

Explanation:
We can use the equation for the speed

where x is the distance and t the time. In this case we know that the time spent was 2 hours and the distance was 150km. By replacing we have

I hope this useful for you
regards