Answer:
average for silk =141"
average for cotton =96"
average for nylon = 70"
if you desire a slower falling parachute to protect the body from damage,
silk is the best
if you desire a faster falling parachute to escape enemy bullets,
nylon is the best
Explanation:
Homework 1
Problem Solving
1. Kelvin and Xavier were doing an investigation on parachutes. One of them suggested that the type of material the parachute was made from had an effect on how long it took to reach the ground. Their results are given in
the table below.
(a) Calculate the average time in seconds for each material.
Time taken for parachute to reach the ground (seconds)
MATERIAL
1st TRY
2nd TRY
3rd TRY
AVERAGE
Sik
144
140 average of 3 = 141
139
Cotton
98
96 average of 3 = 96
94
Nylon
72
68 average of 3 = 70
70
The amount of substance present in a certain object with a given half-life in terms of h can be expressed through the equation,
A(t) = (A(o))(0.5)^(t/h)
where A(t) is the amount of substance after t years and A(o) is the original amount. In this item we are given that A(t)/A(o) is equal to 0.89. Substituting the known values,
0.89 = (0.5)(t / 5730 years)
The value of t from the equation is 963.34 years.
<em>Answer: 963 years</em>
Add an alkaline compound to raise the pH to 7.2.
Answer:
5 moles of Fe
Explanation:
The equation of the reaction is;
2 Al(s) + Fe 2O 3(s) --> 2Fe (s) + Al 2O 3 (s)
Now;
1 mole of Fe2O3 require 2 moles of Al
3 moles of Fe2O3 requires 3 × 2/1 = 6 moles of Al
Hence Al is the limiting reactant.
If 2 moles of Al yields 2 moles of Fe
5 moles of Al yields 5 × 2/2 = 5 moles of Fe
Answer:
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