A 4.0-kilogram penguin sliding across a large, flat icy surface with a constant velocity of 2.0 m s–1. Assuming that the surface is frictionless, what size force is required to keep the penguin travelling at this speed?

The key to stability is feedback between the reservoir and the fluxes into and/or out of the reservoir. assume that the rate of outflow from a reservoir depends on the size of the reservoir according to the following relationship: outflow rate= k x (size of reservoir), where k is a constant. a reservoir of water has a volume of 5000 liters, and the rate of outflow at steady state is 25 liters per minute. what is k? (give both the numerical value and its units.) what is the residence time? what is the relationship between k and the residence time?

Which basic property determines a colored light's placement on the spectrum of visible light? a. speed b. frequency c. amplitude d. velocity

Suppose astronomers built a 140-meter telescope. how much greater would its light-collecting area be than that of the 10-meter keck telescope? express your answer using two sign