2 cars are headed to the same destination leaves a station a minute apart. The one that leaves first travels at 20m/s and the other travels at 30m/s. How long will it take for the later to overtake the former​

When an object is heated it contracts. a. true b. false

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?

Road users moving into your lane, brake lights, and abrupt changes in road surface are a. rare at night b. indicators of potential hazards c. not worth worrying about before you reach them d. no problem for experienced drivers