About how far apart must you hold your hands for them to be separated by 2.8 nano-light-second (the distance light travels in 2.8 ns)? Assume that the speed of light is 2.998*10^8 m/s.

Animals respond in various ways to stimuli detected through their senses. some of these responses are stimulated by the presence of danger. which of these animal responses is the best example of a response to an immediate threat? a) a rooster crows every morning at the first sign of light. b) as something approaches an octopus, it shoots a cloud of ink. c) from late fall until spring, bears hibernate to preserve energy. reactivate d) a dog is getting hot in the sunlight, so he moves to a shaded area.

What is the acceleration of a spaceship that is initially at rest and then speeds up to 220 m/s in 20 seconds

A100-watt light bulb illuminates a solar cell. the electricity from the solar cell operates a water pump that delivers 1 watt of power. what is the efficiency of the system?