Answer:
Ft = 17.48°C
Explanation:
Ft is the final temperature. However, ice absorbs heat during two process of melting and cooling and as such, there is no loss of heat to or from the surrounding hence by conservation of energy.
Therefore,
Heat absorbed by water of 20g = heat rejected by water of 265g.
So; M(ice)[C(ice) [(ΔT) + LH(ice) + C(water)(ΔT)] = C(water) M(water) (ΔT)
So, 20[(2.108) [0 - (-20)] + 333.5 + 4.187(Ft - 0)]] = (285)(4.187) (25 - Ft)
To get;
7513 + 83.74 Ft = 29832.4 - 1193.3 Ft
So factorizing, we get;
83.74 Ft + 1193.3 Ft = 29832.4 - 7513
So; 1277.04 Ft = 22319.4
So; Ft = 22319.4/1277.04 = 17.48°C
Kinetic energy is energy of motion while temperature is a measure of that energy in substances.
From the information given and if the question is complete then;
Absolute temperature is the temperature in Kelvin
To convert degree Celsius to kelvin we normally add 273
that is Kelvin = deg Celsius + 273
Thus since we have been given that the air was at -70 degrees celcius;
then; - 70° C + 273 = 203 K
Therefore; the absolute temperature is 203 K
Answer:

Explanation:
The work function of the metal corresponds to the minimum energy needed to extract a photoelectron from the metal. In this case, it is:

So, the energy of the incoming photon hitting on the metal must be at least equal to this value.
The energy of a photon is given by

where
h is the Planck's constant
c is the speed of light
is the wavelength of the photon
Using
and solving for
, we find the maximum wavelength of the radiation that will eject electrons from the metal:

And since
1 angstrom = 
The wavelength in angstroms is
