Answer:
0.725 kg
Explanation:
Step 1: Given data
- Kinetic energy of the softball (K): 145 J
- Speed of the softball (v): 20.0 m/s
- Mass of the softball (m): ?
Step 2: Calculate the mass of the softball
We will use the following expression.
K = 1/2 × m × v²
m = 2 K / v²
m = 2 × 145 J / (20.0 m/s)²
m = 0.725 kg
The mass of the softball is 0.725 kg.
Which of these what?
This isn't clear, can you put the answer choice or something?
Answer:
44 g
Explanation:
The formula for the number of moles (n) is equal to
.
Since we need to find the mass, we derive it from the formula of the number of moles and we get that mass = n x molecular weight .
The molecular weight of
= 12 g/mol (from the carbon) + 19x4 g/mol (from the 4 fluorine atoms)= 88 g/mol
We plug in the numbers in the derived formula for the mass and we get :
mass = n x molecular weight = 0.5 mol x 88 g/mol = 44 g
26.7% is the percent composition by mass of sulfur in a compound named magnesium sulfate. Explanation: Molar mass of compound = 120 g/mol.