Why does a black smith heat the iron block before hammering it to change its shape ?

If you quadruple the temperature of a black body, by what factor will the total energy radiated per second per square meter increase? 1,024 64 16 4 256 submit answer

The uniform slender bar rests on a smooth horizon- tal surface when a force f is applied normal to the bar at point a. point a is observed to have an initial acceleration aa of 20 m/s2, and the bar has a corre- sponding angular acceleration of 18 rad /s2. deter- mine the distance b.

What structural formula represents 4 electrons shared between two atoms?