There had been new discoveries of chemicals that have been added to the periodic table in recent years
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
Answer:
Here's what I get
Explanation:
A physical property is one you can observe without changing the chemical composition of a substance.
A chemical property is one you can observe only by changing the chemical composition of a substance.
In this problem, examples of physical properties are:
- Colour
- Lustre
- Melting point
- Boiling point
- Density
- Malleability
- Ductility
- Conduction of electricity
Examples of chemical properties are:
- Burning in air
- Reaction with chlorine
Answer:
CH
Explanation:
When a hydrocarbon burns, there are only two products. These are hydrogen and carbon iv oxide. The general equation for burning a hydrocarbon is shown below:
Fuel + O2 → CO2 + H2O
Since 9g Of water is formed, we can get the number of moles of hydrogen and the mass of hydrogen.
We now need to get the actual moles of carbon and hydrogen in the hydrocarbon to know what the chemical formula is.
The number of moles of hydrogen and its mass can be obtained from that of water. The number of moles of water is simply the mass of water divided by the molar mass. The molar mass of water is 18g/mol. The number of moles is thus 9/18 which is 0.5. Since there are two atoms of hydrogen in one molecule of water, the number of moles of hydrogen is thus 2 * 0.5 which equals one mole.
The mass of hydrogen is thus the number of moles of hydrogen * the molar mass of hydrogen which is
1 * 1 = 1g
Hence, the mass of the carbon in the hydrocarbon is 13 - 1 = 12g
The number of moles of carbon present is thus 12/12 which equals 1.
Since the mole ratio is 1 to 1 , the formula of the hydrocarbon is thus CH