in a particular inertial frame s, two events occur a distance c△t apart and one event occurs before the other by a time at. an observer who is travelling at speed v relative to s in a direction parallel to the line joining the events notes that the events are only δt/2 apart. determine v/c. 8 marks c) a second observer is travelling in the same direction as the first observer but at a speed of 4c/5 as measured in s. in terms of δt, what is the time interval between the events according to this observer? [5 marks) d) what is the speed of the second observer as determined in the rest-frame of the first 6 marks observer?

Asample of a gaseous substance changes into liquid. this process is called (blank) and it takes place when heat is (blank) a gaseous system

In a thunderstorm, charge builds up on the water droplets or ice crystals in a cloud. thus, the charge can be considered to be distributed uniformly throughout the cloud. for the purposes of this problem, take the cloud to be a sphere of diameter 1.00 kilometer. the point of this problem is to estimate the maximum amount of charge that this cloud can contain, assuming that the charge builds up until the electric field at the surface of the cloud reaches the value at which the surrounding air breaks down. this breakdown means that the air becomes highly ionized, enabling it to conduct the charge from the cloud to the ground or another nearby cloud. the ionized air will then emit light due to the recombination of the electrons and atoms to form excited molecules that radiate light. in addition, the large current will heat up the air, resulting in its rapid expansion. these two phenomena account for the appearance of lightning and the sound of thunder. take the breakdown electric field of air to be eb=3.00ă—106n/c. part a estimate the total charge q on the cloud when the breakdown of the surrounding air is reached. express your answer numerically, to three significant figures, using ďµ0=8.85ă—10â’12c2/(nâ‹…m2) .

The scalar triple product computes the magnitude m of the moment of a force vector f about a specified line. it is m = (r × f) · n, where r is the position vector from the line to the point of application of the force and n is a unit vector in the direction of the line. use matlab to compute the magnitude m for the case where f = [12, −5, 4] n, r = [−3, 5, 2] m, and n = [6, 5, −7].