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:
The fundamental frequency and length of the pipe are 100 Hz and 1.7 m.
Explanation:
Given that,
Frequency f = 550 Hz
Frequency f' = 650 Hz
We know that,
AMT pipe is open pipe.
(b). We need to calculate the length of the pipe
Using formula of organ pipe

For 550 Hz,
...(I)
For 650 Hz,
...(II)
From equation (I) and (II)



(a). We need to calculate the fundamental frequency for n = 1
Using formula of fundamental frequency

put the value of L


Hence, The fundamental frequency and length of the pipe are 100 Hz and 1.7 m.
Answer:
Explanation:
Voltage and current in resistors
A graph of current against potential difference shows you how the current flowing through a component varies with the potential difference across it. The current flowing through a resistor at a constant temperature is directly proportional to the potential difference across it.
Answer:
D) 10 200 m
Explanation:
Speed is known as the rate of change of distance.
distance = speed * time
= 85 ms⁻¹ * 120 s
= 10200 m
Because in reality there are frictional forces acting on the ball, against the direction of its motion. In fact, because of the friction between the ball and the surface, the ball loses little by little its energy, so its velocity decreases and eventually it stops.
In an ideal world with no friction, there would be no forces acting on the ball, so its energy must be conserved and this means that the ball would continue its motion forever.