Answer:
A heat engine is a type of engine, (like the motor in a car) that produces ... Heat engines do just the opposite; they take the energy from being warm ... using a flame to heat water into steam, then using the steam to turn a turbine. ... is the percentage of energy input that the engine can convert to useful work.
Explanation:
hope this helps
and i hope its right
Answer: No
Explanation:
- Law of definite proportions is a case from the Law of conservation of energy (matter) which states that "mass can neither be created nor destroyed, but changed from one form to another."
- Adding coefficients to a chemical equation confirms that there is the same number of atoms on both sides of a reaction; therefore, matter has not been created or destroyed but reorganized to give new substrates.
Example : 2 Mg + O2 → 2 MgO
In the balanced equation above, 2 moles of Mg reacts with 1 mole of O2 to produce 2 moles of MgO.
mass of 2 moles of Mg = 24×2= 48 grams
mass of 1 mole of O2 = 16+16 = 32 grams
total mass of reactants = 48 + 32 = 80 grams
mass of 2 moles of MgO = (24+16) ×2 = 80 grams
total mass of products = 80 grams
It is clear that the number of grams of matter before and after the reaction is the same and equals to 80 grams, so obeys the law of definite proportions..
Answer:
efficiency of heating with this oven is 51 %
Explanation:
to raise the temp of 200 ml of coffee from 30°C to 60°C the energy input to microwave oven is:
1100 J/s x 45 = 49,500 J
AT 100% efficiency
For 1°C the energy required to raise the temperature of 1 ml = 4.2 J
So for 30 C°, 1°C the energy required to raise the temperature of 200 ml =
Q = (4.2) (200)(30) = 25,200 J
efficiency = 25,200/49,500 = 0.51 = 51%
Answer:
Explanation
Hardness has been defined the level of difficulty with a smooth surface of a mineral may be scratched. The hardness of a mineral species is upon the strength of the bonds which compose its crystal structure Hardness is measured of how easily a material can be scratched or indented Hard materials are often very brittle.
The correct answer would be 0.1505 M/s. Given the rate of disapperance of HBr, we can easily calculate the rate of apearance of the products by looking at the coefficients of the substances in the reaction. In this case, for every two moles of HBr, 1 mole of Br2 is being produced so the reaction rate would be:
- 1/2 (r(HBr)) = rBr2
- 1/2 (-0.301) = rBr2
Rate of appearance of Br2 = 0.1505 M/s
