Complete question:
A ball with a weight of 0.5 kg is sitting on a shelf that is 3 meters high. What is the gravitational potential energy of the ball ?
Help me! This is 8th grade sci btw
Answer:
the gravitational potential energy of the ball is is 14.7 J.
Explanation:
mass of the ball, m = 0.5 kg
height above the ground on which the ball is sitting, h = 3 m
The gravitational potential energy of the ball is calculated as follows;
P.E = mgh
P.E = 0.5 x 9.8 x 3
P.E = 14.7 J
Therefore, the gravitational potential energy of the ball is is 14.7 J.
Answer:
The percentage composition of the elements of the compound in the three samples is the same.
Explanation:
<em>The law of definite proportions states that all pure samples of a particular chemical compound contain the same elements in the same proportion by mass.</em>
Sample A:
Mass of A = 4.31 g; mass of Z = 7.70 g
Total mass of sample = 12.01
Percentage mass of A in the sample = (4.31 * 100)/12.01 = 35.9 %
Percentage mass of Z in the sample = (7.70 * 100)/12.01 = 64.1 %
Sample B:
Percentage mass of A in the sample = 35.9 %
Percentage mass of Z in the sample = 64.1 %
Sample C:
Mass of A = 0.718 g; Total mass of sample = 2.00 g
mass of Z = mass of sample - mass of A = 2.00 g - 0.718 g = 1.282 g
Percentage mass of A in the sample = (0.718 * 100)/2.00 = 35.9 %
Percentage mass of Z in the sample = (1.282 * 100)/2.00 = 64.1 %
From the calculations, it can be seen that the percentage composition of the elements in the compound is the same for the three samples.
Answer:
A. All of the answer choices are correct.
Explanation:
Giant sequoia trees
<u>They are long - living and the largest living organism on the planet Earth .</u>
They are majorly found in the western slopes of the Sierra Mountains present in the California .
These tress can grow to an average height of 50 to 85 meters , with diameter measuring 6 to 8 meters .
- They are also responsible for the generation of carbon dioxide via cellular respiration .
- It is the net sink of the carbon dioxide .
- It incorporates the carbon dioxide into the biomass .
Answer:
50.00 g of NO
Explanation:
Remember that the balanced chemical reaction equation is indispensable in solving any question that has to do with stoichiometry. Hence the first step in solving the problem is noting down the balanced chemical reaction equation.
2NO(g) + O2 (g)→ 2NO2(g)
Now we try to find out the reactant in excess. The reactant in excess gives the greater mass of product.
For O2;
From the balanced reaction equation;
32 g of O2 yields 92g of NO2
16.00g of O2 will yield 16.00×92/32 = 46g of NO2
For NO;
30g of NO yields 92g of NO2
80.00 g of NO yields 80.00 × 92/30 = 245.33 g of NO2
Hence NO is the reactant in excess.
If 1 mole of O2 reacts with 2 moles of NO2 according to the balanced reaction equation
Then 32 g of O2 reacts with 60g of NO according to the balanced reaction equation
16.00 g of O2 reacts with 16.00 × 60 /32 = 30 g of NO
Hence mass of excess reactant used in the reaction = total mass of NO- mass of NO reacted= 80.00g -30.00g = 50.00 g of NO
Hence the mass of excess reactant used in the reaction is 50.00 g of NO
You need 4 H2 molecules and 2 O2 molecules.
This is because water is H2O which is 2 Hydrogen and 1 Oxygen so if you want to make 4 water molecules, you’ll need 8 hydrogen and 4 oxygen.
Given H2 you need 4 because 4•2 is 8 and for O2 you need 2 because 2•2 is 4.
I hope this makes sense.