The initial temperature is 137.34 °C.
<u>Explanation:</u>
As the specific heat formula says that the heat energy required is directly proportional to the mass and change in temperature of the system.
Q = mcΔT
So, here the mass m is given as 23 kg, the specific heat of steel is given as c = 490 J/kg°C and the initial temperature is required to find with the final temperature being 140 °C. Also the heat energy required is 30,000 J.
ΔT =
ΔT =
Since the difference in temperature is 2.66, then the initial temperature will be
Final temperature - Initial temperature = Change in temperature
140-Initial temperature = 2.66
Initial temperature = 140-2.66 = 137.34 °C
Thus, the initial temperature is 137.34 °C.
Answer:
According to my search, the answer is this.
Black holes come in several different sizes which are defined by their mass. Small black holes are usually the result of a relatively short and violent collapse of a star.
Explanation:
It only has mass. The amount of matter that has fallen into the black hole determines its mass. The more mass/matter a singularity has the larger its event horizon. So, the greater the black hole's mass the larger it is.
Answer:
12.4×10^3 V
Explanation:
From E=hc/wavelength= eV
The voltage becomes
V= hc/e* wavelength
V= 6.63*10^-34*3*10^8/1.6*10^-19*1*10^-10
Note that the energy of the photon is transferred to the electron. That is the basic assumption we have applied in solving this problem. The kinetic energy of the electron is equal to the product of the electron charge and the acceleration potential.
Al 1s²2s²2p⁶3s²3p¹ - 3e⁻ → Al³⁺ 1s²2s²2p⁶
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