Answer:
I think it's a catalyst.
Explanation:
Definition: a substance that increases the rate of a chemical reaction without itself undergoing any permanent chemical change
Answer:
the cost of operating the light bulb is 72 cents.
Explanation:
Given;
cost of electricity, C = 6 cents / kW.h
power of light bulb, P = 100 W
time of light power consumption, t = 4 hours per day for 30 days
total time = 4 hours x 30 = 120 hours
Power consumed by the light bulb is calculated as;
P = 100 x 120 = 12000 w.h = 12 kW.h
Cost of power consumption = 6 cents/kWh x 12 kWh
= 72 cents
Therefore, the cost of operating the light bulb is 72 cents.
The density of an object is given by:
D = M/V
D = density, M = mass, V = volume
The volume of the cube V is given by:
V = s³
where s = side length
Make a substitution:
D = M/s³
Given values:
M = 20kg, s = 20×10⁻²m
Plug in and solve for D:
D = 20/(20×10⁻²)³
D = 2500kg/m³
The answer is 2.49 x 10^5 KJ. This was obtained (1) use the formula for specific heat to achieve Q or heat then (2) get the energy to melt the copper lastly (3) Subtract both work and the total energy required to completely melt the copper bar is achieved.
