I need Help Please A bar of iron with mass 45 kg is cooled from 50℃ to 20℃. How much thermal energy does the bar of iron lose? The specific heat of iron is 470 kg/kg*C.

Light traveling in a medium with a refractive index 1.19 is incident on a plate of another medium with index of refraction 1.79. at what angle of incidence is the reflected light fully polarized?

How to tell if a molecule is polar or nonpolar with electronegativity

For the car in the picture ,in which direction is the normal force? -into the screen -down -out of the screen -up