The doppler effect is used by weather forecasters to measure what

Aspring with a mass of 2 kg has a damping constant 14 kg/s. a force of 3.6 n is required to keep the spring stretched 0.3 m beyond its natural length. the spring is stretched 0.6 m beyond its natural length and then released. find the position of the mass at any time t. (assume that movement to the right is the positive x-direction and the spring is attached to a wall at the left end.)

How have the competing explanations' experiments on atoms affected the development of the atomic model?

When the force acting on an object points at least partially in the direction of the motion the work done is considered to be negative