Q. A horseshoe has a surface area of 43 cm^2, and a blacksmith heats it to a red-hot 810 degrees.

At what rate does it emit energy by radiation?

Q. A 11.0-g bullet is fired horizontally into a 109-g wooden block that is initially at rest on a frictionless horizontal surface and connected to a spring having spring constant 142 N/m. The bullet becomes embedded in the block. If the bullet-block system compresses the spring by a maximum of 90.0 cm, what was the speed of the bullet at impact with the block.