Radiation makes it impossible to stand close to a hot lava flow. calculate the rate of heat transfer by radiation from 1.00 m^2 of 1250°c fresh lava into 34.0°c surroundings, assuming lava's emissivity is 1.00

3.045 x 10^5 Joule per second

Explanation:

A = 1 m^2

T = 1250 degree C = 1250 + 273 = 1523 K

To = 34 degree C = 34 + 273 = 307 K

e = 1

Stefan's constant, σ = 5.67 x 10^-8 watt per meter squared per kelvin to the fourth

Use of Stefan's Boltzmann law

Energy radiated per unit time

E = σ A e (T^4 - To^4)

E = 5.67 x 10^-8 x 1 x 1 (1523^4 - 307^4)

E = 3.045 x 10^5 Joule per second

thermal energy is the answer

c) up is the direction the magnetic force is acting on the charge.