Answer:
71195 seconds or 19.8 hours
Explanation:
Because the steel will be melted, beginning from room temperature, energy is needed to heat it from room temperature to 1600°C and another to melt it at 1600°C.
We take room temperature to be 27°C, the specific heat capacity of steel to be 420 J/kg/K and the specific latent heat of fusion of steel to be 440 J/kg.
The heat required to heat the steel from room temperature to 1600°C is given by
is the mass, 
is the specific heat capacity and 
is the change in temperature.
The heat required to melt it at 1600°C is
is the mass and 
is the specific latent heat of fusion of steel.
Adding both, the heat required is 
Because the oven is 65% efficient, its output power = 
Now, energy = power * time
Time = Energy/power
Answer:
D
Explanation:
Copper wire at higher temperature
The problem statement is simply asking us to convert units. We convert from units of ft^3 to units of m^3. To do this, we need a conversion factor. For this case, we use 1 m is equal to 3.28084 ft. We do as follows:
5.0 ft^3 ( 1 m / 3.28084 ft )^3 = 0.1416 m^3
Answer:
D
Explanation:
I just took the test and C was wrong, do not listen to that answer. It is "All of the above"
distance d = 5 km = 5 x 1000 m = 5000 m
time taken = 25 minute = 25 x 60 sec = 1500 sec
average velocity V = d/t
V = 5000/1500
V = 3.33 m/s towards east
