A girl of mass 48kg is rescued from a building fire by leaping into a firefighters' net. The window from which she leapt was 12 metres above the net. She lands in the net so that she is brought to a stop in 0.45 seconds. During this interval, a) What is her change in momentum?
b) What is the impulse on the net due to girl?
c) What is the average force on the net due to girl?

If a rock is thrown upward on the planet mars with a velocity of 12 m/s, its height (in meters) after t seconds is given by h = 12t − 1.86t2. (a) find the velocity of the rock after two seconds. m/s (b) find the velocity of the rock when t = a. 12−3.72a m/s (c) when will the rock hit the surface? (round your answer to one decimal place.) t = s (d) with what velocity will the rock hit the surface? m/s

Which component of the earth’s atmosphere is decreased due to photosynthesis?

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