Recent content by john merrick

i did this t=Q/I 1C/0.5A =2s the book says E=VIt 120J=12v x 0.5A x t t=20s. i don't understand why the answer is not 2s.

you are right i think what they want is the work done on the roller coaster by a given force( you pulling it) i'll put both answers.

that is what I'm thinking. but this is just one of the questions... there is another 4 or 5 questions related to this roller coaster problem. i only put up the information necessary to answer question 1.

question states that roller coaster comes to rest.

height to point A is 65m. no friction. comes to rest at point A. total mass of the roller coaster is 650 kg. the work-energy theorem states that the net work done on an object is equal to the change in kinetic energy of the object. kinetic energy is E=1/2mv^2. initial velocity is...

i got no problem with that but they are marking on the correct significant digits. so you just can't but whatever you want.

my problem is not how you get the answer... 425.16Hz for approaching. it has to be do the right amount of significant digits. so it should be 1 significant digit which would mean 400hz. which would make no sense since i started with 400hz. i'm assuming they should have written the question...