a student removes a 10.5kg stereo from a shelf that is 18.2 m high. the amplifier is lowered at a constant speed to a height of 0.75 m. what is the work done by (a) the person and (b) the gravitational force that acts on the amplifier?

The graph below represents the work done by a student while running up flights of stairs. determine the student's power output after 10 seconds: 1600 j/s 8000 j/s 160 j/s 800 j/s

Global warming will produce rising sea levels partly due to melting ice caps but also due to the expansion of water as average ocean temperatures rise. to get some idea of the size of this effect, calculate the change in length of a column of water 1.00 km high for a temperature increase of 1.00ºc. note that this calculation is only approximate because ocean warming is not uniform with depth. (answer in ×10^{-3} −3 m)

Scientific models are based on current knowledge, which can limit their effectiveness when new discoveries are made.