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 Answer is D. Suspending a heavy weight with a strong chain.
Answer:
163.2g
Explanation:
First let us generate a balanced equation for the reaction. This is shown below:
4Al + 3O2 —> 2Al2O3
From the question given, were were told that 3.2moles of aluminium was exposed to 2.7moles of oxygen. Judging by this, oxygen is excess.
From the equation,
4moles of Al produced 2moles of Al2O3.
Therefore, 3.2moles of Al will produce = (3.2x2)/4 = 1.6mol of Al2O3.
Now, let us covert 1.6mol of Al2O3 to obtain the theoretical yield. This is illustrated below:
Mole of Al2O3 = 1.6mole
Molar Mass of Al2O3 = (27x2) + (16x3) = 54 + 48 =102g/mol
Mass of Al2O3 =?
Number of mole = Mass /Molar Mass
Mass = number of mole x molar Mass
Mass of Al2O3 = 1.6 x 102 = 163.2g
Therefore the theoretical of Al2O3 is 163.2g
The molar mass of carbon is 12, hydrogen is 1, and
nitrogen is 14, hence the ratio are:
C = 38.65 / 12 = 3.22
H = 16.25 / 1 = 16.25
N = 45.09 / 14 = 3.22
Divide the three by the lowest ratio which is 3.22:
C = 3.22 / 3.22 = 1
H = 16.25 / 3.22 = 5
N = 3.22 / 3.22 = 1
So the empirical formula is:
CHN
It smells so bad that no one or animal will get near it
