Explain why placing wheels under a heavy box reduces the necessary force required to push it along at a constant speed. Please describe the types of friction (static, sliding, kinetic, rolling, or fluid) this is showing and how it is different from other types of friction.

rolling

Explanation:

It is usually greater than static friction. ... The coefficient of kinetic friction is less than the coefficient of static friction. When the box is stationary, w|| equals the force of static friction, but once the box starts moving, the sliding reduces the normal force, which in turn reduces the friction.

absorption lines are where light has been absorbed by the atom thus you see a dip in the spectrum whereas.

emission spectra have spikes in the spectra due to atoms releasing photons at those wavelengths.

explanation:

hey , the answer is c