A 145-g baseball is thrown so that it acquires a speed of 25 m/s. What was the net work done on the ball to make it reach this s
1 answer:
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Answer:
Explanation:
The acceleration of an object is given by:
where
v is the final velocity
u is the initial velocity
t is the time interval it takes for the velocity to change from u to v
For the rocket in this problem,
u = 20,000 m/s
v = 24,000 m/s
t = 55.0 - 5.0 = 50.0 s
Substituting,
Answer:
The atomic weight in g/mole of the metal (molar mass) is 8.87.
Explanation:
To begin, it is possible to assume that, as a sample, it has 100 g of the compound. This means that:
- 52.92% metal: 52.92 g M
- 47.80% oxygen: 47.80 g O
Using the molar mass of oxygen, which is 16 g / mol, it is possible to calculate the amount of moles of oxygen present in the sample using the rule of three:
moles of oxygen=2.9875
The chemical formula of metal oxide tells you that:
2 M⁺³ + 3 O²⁻ ⇒ M₂O₃
In the previous equation you can see that you need 3 oxygen anions to react with two metal cations. Then:
You have 52.92 g of metal in the sample, then the molar mass of the metal is:
molar mass≅ 8.87 g/mol
<u><em> The atomic weight in g/mole of the metal (molar mass) is 8.87.</em></u>
The closest match to this value is Beryllium (Be), which has an atomic mass of 9.0122 g / mol.