<u>Answer:</u> The percent composition of 
in taconite is 37.6 %.
<u>Explanation:</u>
We are given:
Mass of taconite pellets = 1 ton = 907185 g (Conversion factor: 1 ton = 907185 g)
Mass of iron produced = 545 lb = 247212 g (Conversion factor: 1 lb = 453.6 g )
We know that:
Molar mass of iron = 55.85 g/mol
Molar mass of = 231.53 g/mol
1 mole of contains 3 moles of iron atom and 4 moles of oxygen atom
(3 × 55.85) = 167.55 g of iron is produced from 231.53 grams of
So, 247212 grams of iron will be produced from = 
of
To calculate the percentage of in taconite, we use the equation:
Mass of taconite = 907185 g
Mass of = 341611.43 g
Putting values in above equation, we get:
Hence, the percent composition of in taconite is 37.6 %.
Potential energy is energy due to an object's height above the ground.
Potential energy = mass x gravity x height
Kinetic energy is energy due to the motion of the object.
Kinetic energy = 1/2 x mass x velocity²
1.
The ball is not moving and is at a height above the ground so it has only potential energy.
P.E = 2 x 9.81 x 40
P.E = 784.8 J
2.
The ball is moving and has a height above the Earth's surface so it has both kinetic and potential energy.
P.E = same as part 1 = 784.8 J
K.E = 1/2 x 2 x 5²
K.E = 25 J
3.
The ball has no height above the Earth's surface and is moving so it has only kinetic energy.
K.E = 1/2 x 2 x 10²
K.E = 100 J
4.
50000 = 1/2 x 1000 x v²
v = 10 m/s
5.
39200 = 200 x 9.81 x h
h = 20.0 m
6.
12.5 = 1/2 x 1 x v²
v = 5 m/s
98 = 1 x 9.81 x h
h = 10.0 m
