Answer:
Number mole of calcium (Ca) = 1.4942 x 10⁻⁷ (Approx.)
Explanation:
Given:
Number of atom in (Ca) = 9 x 10¹⁶
Find:
Number mole of calcium (Ca)
Computation:
Number mole of calcium (Ca) = Number of atom in (Ca) / Avogadro's number
Number mole of calcium (Ca) = (9 x 10¹⁶) / (6.023 x 10²³)
Number mole of calcium (Ca) = 1.4942 x 10⁻⁷ (Approx.)
45.0g
I hope that this helps
<h3>
Answer:</h3>
89.88° C
<h3>
Explanation:</h3>
<u>We are given;</u>
- Mass of gold cylinder as 75 g
- specific heat of gold is 0.129 J/g°C
- Initial temperature of gold cylinder is 65°C
- Mass of water is 500 g
- Initial temperature of water is 90 °C
We are required to calculate the final temperature;
- We know that Quantity of heat is given by the product of mass, specific heat capacity and change in temperature.
<h3>Step 1: Calculate the quantity of heat absorbed by the Gold cylinder</h3>
Assuming the final temperature is X° C
Then; ΔT = (X-65)°C
Therefore;
Q = 75 g × 0.129 J/g°C × (X-65)°C
= 9.675X - 628.875 Joules
<h3>Step 2: Calculate the quantity of heat released by water</h3>
Taking the final temperature as X° C
Change in temperature, ΔT = (90 - X)° C
Specific heat capacity of water is 4.184 J/g°C
Therefore;
Q = 500 g × 4.184 J/g°C × (90 - X)° C
= 188,280 -2092X joules
<h3>Step 3: Calculate the final temperature, X°C</h3>
we know that the heat gained by gold cylinder is equal to the heat released by water.
9.675X - 628.875 Joules = 188,280 -2092X joules
2101.675 X = 188908.875
X = 89.88° C
Thus, the final temperature is 89.88° C
Answer:
The person’s kinetic energy is 1,025 J
Explanation:
Kinetic energy is a form of energy. It is defined as the energy associated with bodies that are in motion and this energy depends on the mass and speed of the body.
Kinetic energy is defined as the amount of work necessary to accelerate a body of a given mass and in a position of rest, until it reaches a given speed. Once this point is reached, the amount of accumulated kinetic energy will remain the same unless there is a change in speed or the body returns to its state of rest by applying a force.
Kinetic energy is represented by the following formula:
where Ec is kinetic energy, which is measured in Joules (J), m is mass measured in kilograms (kg), and v is velocity measured in meters over seconds (m/s).
In this case:
- v= 5
Replacing:
Solving:
Ec= 1,025 J
<u><em>The person’s kinetic energy is 1,025 J</em></u>
