How many joules does it take to hear 4250g of lead from 150c to 1275c

An incident ray through the focal point of a spherical mirror will: reflect through the center of curvature. reflect back through the focal point. reflect parallel to the principle axis. reflect the same direction as the incident ray.

You are given a vector a = 125i and an unknown vector b that is perpendicular to a. the cross-product of these two vectors is a × b = 98k. what is the y-component of vector b?

Why is the energy that results from a roller coaster's position at the top of a hill referred to as potential energy?