Astudent determined to test the law of gravity for himself walks off a skyscraper 900 ft high, stopwatch in hand, and starts his free fall (zero initial velocity). five seconds later, superman arrives at the scene and dives off the roof to save the student. (a) what must superman’s initial velocity be in order that he catch the student just before the ground is reached? (b) what must be the height of the skyscraper so that even superman can’t save him? (assume that superman’s acceleration is that of any freely falling body.)

In a given chemical reaction, the energy of the products is greater than the energy of the reactants. which statement is true for this reaction?

First, launch the video below. you will be asked to use your knowledge of physics to predict the outcome of an experiment. then, close the video window and answer the question at right. you can watch the video again at any point. part a as in the video, we apply a charge +q to the half-shell that carries the electroscope. this time, we also apply a charge –q to the other half-shell. when we bring the two halves together, we observe that the electroscope discharges, just as in the video. what does the electroscope needle do when you separate the two half-shells again? view available hint(s) as in the video, we apply a charge + to the half-shell that carries the electroscope. this time, we also apply a charge – to the other half-shell. when we bring the two halves together, we observe that the electroscope discharges, just as in the video. what does the electroscope needle do when you separate the two half-shells again? it deflects more than it did at the end of the video. it deflects the same amount as at end of the video. it does not deflect at all. it deflects less than it did at the end of the video. submit

Apotter's wheel moves uniformly from rest to an angular speed of 0.20 rev/s in 32.0 s. (a) find its angular acceleration in radians per second per second. rad/s2 (b) would doubling the angular acceleration during the given period have doubled final angular speed?