Is a net force of 0n unbalanced or balanced?

To do work, this truck uses energy stored in chemical fuel and an electrical battery. how much total energy does this truck put out?

Modern physics a photon emitted from an excited hydrogen atom has an energy of 3.02 electron volts. which electron energy-level transition would produce this photon? a. n=1 to n=6 b. n=2 to n=6 c. n=6 to n=1 d. n=6 to n=2 i chose b but the correct answer is d can someone tell me why? and what's the difference?

Write a full page that sumerizes thermodynamics it’s from the website visionlearnig