Four railroad cars, all with the same mass of 20,000 kg, sit on a track. A fifth car of identical mass approaches them with a velocity of 15 m/s. This car collides and couples with the other four cars. What is the velocity of the five coupled cars after the collision?

The simple interest on a loan of $200 at 10 percent interest per year is $10 per year until the loan is paid off. $15 per year until the loan is paid off. $20 per year until the loan is paid off. $25 per year until the loan is paid off.

The us government wants to allocate billions of dollars in the next 10 years to assure our future energy security. the funds will be spread among a variety of possible energy resources. where do you think the government should put the greatest support: solar energy, wind energy, clean coal, oil exploration, gas exploration, or a combination of sources? are there other efforts that should be explored? support your position with cited information for both questions.

Use the illustration to describe how the electromagnetic spectrum changes as its frequency moves from radio waves to higher energy gamma waves in terms of wavelength and amplitude.