Answer:
2 times the diameter of the original wire.
Explanation:
Let's call the resistivity of the wire. The original resistance of the wire is given by
where L is the length of the wire and A is the cross-sectional area. Writing the area as
where d is the diameter and d/2 corresponds to the radius, we can rewrite the resistance of the wire as
Which can be rewritten solving for d, the diameter:
Now, we know that the wire must be replaced by a wire with same material (so, same resistivity ), but with 4 times long, which means the new length is . Substituting this into the formula, and keeping in mind that the resistance R must remain the same, we find the new diameter:
so, the diameter must be
2 times the diameter of the original wire.
<span>The formulas are,
v1d1² = v2d2² ........ (1)
h = (v2²-v1²)/2g ...... (2)
Given that,
v1 = 1.71 m/s
we assume that the stream has decreased by a factor
d2 =0.805d1
then,
v1d1² = v2 (0.805d1)²
cancelled both side d1² then we get,
v1 = v2 (0.805)²
v1 = v2 (0.648025)
Sub v1 = 1.71,
1.71 = v2 (0.648025)
v2 = 1.71/0.648025
v2 = 2.638787083831642
v2 = 2.64 m/s
The vertical distance formula,
h = (v2²-v1²)/2g
We know that value of gravity constant is 9.8 m/s²
h = {(2.64)² - (1.71)²)/2(9.8)
h = {(6.9696) - (2.9241)}/19.6
h = (4.0455)/19.6
h = 0.2064030612244898
h = 0.21 cm
Therefore, the vertical distance h = 0.21 cm.</span>
B would be the correct answer because organic things are made from living things such as,plants