Zinc = 7/18
Divide 4.9 by 7 = 0.7
Multiply by 18 = 12.6
The answer is 12.6 lbs of alloy. Sorry if I'm wrong
Answer:
It will take 5.61 seconds for the coin to reach the stream.
Step-by-step explanation:
The height of the coin, after t seconds, is given by the following equation:

How long will it take the coin to reach the stream?
The stream is the ground level.
So the coin reaches the stream when h(t) = 0.


Multiplying by (-1)

Solving a quadratic equation:
Given a second order polynomial expressed by the following equation:
.
This polynomial has roots
such that
, given by the following formulas:



In this question:

So




Time is a positive measure, so we take the positive value.
It will take 5.61 seconds for the coin to reach the stream.
Multiplying x^2 by 5 stretches the graph vertically by a factor of 5. Try graphing both x^2 and 5x^2 and see for yourself that this is correct.