A rocket, weighing 4.36 x 103kg, has an engine that provides an upward force of 1.2 x 105N. It reaches a maximum speed of 860 m/s. For how much time must the engine burn during the launch in order to reach this speed?

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