A football player with a mass of 110 kg runs into a stationary tackling sled that has a mass of 250 kg. Both the player and sled move together and come to rest 25 cm from the impact. If the coefficient of kinetic friction between the sled and the ground is 0.50, what was the initial speed of the football player

An electric power distributor charges residential customers $0.10 per kilowatt-hour (kwh). the company advertises that "green power" is available in 150 kwh blocks for an additional $4 per month. (green power is generated from solar, wind power, and methane sources.) if a certain customer uses an average of 391 kwh per month and commits to one monthly 150 kwh block of green power, what is her annual power bill