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(I) What is the weight of a 68-kg astronaut ($a$) on Earth, ($b$) on the Moon ($g =1.7 m/s^2$) ($c$) on Mars ($g = 3.7 \,m/s^2$) ($d$) in outer space traveling with constant velocity?
(II) A person has a reasonable chance of surviving an automobile crash if the deceleration is no more than 30 $g$'s. Calculate the force on a 65-kg person accelerating at this rate.What distance is traveled if brought to rest at this rate from 95 km/h?
(I) A 7150-kg railroad car travels alone on a level frictionless track with a constant speed of 15.0 m/s. A 3350-kg load, initially at rest, is dropped onto the car. What will be the car's new speed?
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welcome to our next unit, where we will be discussing electromagnetic waves. This is going to be a unit all about how electric fields and magnetic fields are related to each other. Remember, when I talk about electric fields, I am talking about the vector fields coming off of charges and also the fields coming off of moving charges. So we have magnetic fields for moving charges and electric fields for stationary charges. Though a moving charge will also produce a new electric field. And we're going to find that these two are very related to each other. And we've known this for a very long time because even before we understood everything about thes using simple Galilean transformations, we were able to see that on electric field in a reference frame be is equal to the electric field. In a reference frame, a plus, the velocity of reference frame be with respect to a crossed into the magnetic field with respect to reference frame. A. So remember what we're talking about here are we have reference frames a and be and B is moving with respect to a and we're going to look at a point in space and analyze it from both perspectives and this is what we come up with. Is the transformation going from electric field with respect to a two electric filled with respect to be? If we were due to do magnetic field, we would come up with a similar sort of result where the magnetic field, with respect to B is equal to the magnetic field with respect to a minus one over C squared times, the velocity of be with respect to a crossed in the into the electric field With respect we're see here is equal to one over epsilon. Not you not Pardon me. The square root of absolutely not immune up and is the speed of light three times 10 to the 8 m per second. So you may recall that light is an electromagnetic wave, sometimes also called electromagnetic radiation. Okay, eso these transformations work okay, except when we start to thinking about Faraday's law. When we think about Faraday's law and this experiment, we run where we have a circuit that's moving into some magnetic field and as we move it in here, we know that it's we should get an induced e m f, which will come as a result of an induced electric field. So if we were to think about a reference frame A that is at rest with respect to this and if reference frame be that is not at rest with respect to it, then what is it that well, you would observe? Well, reference frame A. Because it doesn't see any motion would suppose that there is no electric field here. It expects that there to be zero electric field. And how does that influence our transformations? Well, when we go to find electric field with respect to be, what we find is we end up with just V cross be. And when we go to do magnetic field, we find that we just get be again. So clearly we've had a breakdown here. There's definitely a connection between electric field and magnetic field, but something about the transformations we just look that fails when we try to talk about induced electric fields. So we're going to talk about what we need to do with our equations relating these two fields in order to solve this problem