P4 One of the sides of the frame shown in the figure can move. The frame is in uniform magnetic field of B which is perpendicular to the plane of the frame. At the time of t = 0 the magnetic field begins to decrease as B(t) = (k is a constant). At what speed should the side of the frame be moved in order not to induce electric current in it? LE B b. B

Susan is running to the right, in the +x-direction, at 2 m/s. A bird flies past her, traveling to the left at 10 m/s. What is the bird's velocity in Susan's reference frame? Susan is running to the right, in the +x-direction, at 2 m/s. A bird flies past her, traveling to the left at 10 m/s. What is the bird's velocity in Susan's reference frame? 12 m/s 10 m/s 8 m/s -8 m/s -10 m/s -12 m/s

Two trees are 600 m apart. You are standing exactly halfway between them and your lab partner is at the base of tree 1. Lightning strikes both trees.a. Your lab partner, based on measurements he makes, determines that the two lightning strikes were simultaneous. What did you see? Did you see the lightning hit tree 1 first, hit tree 2 first, or hit them both at the same instant of time? Explain.b. Lightning strikes the trees again. This time your lab partner sees both flashes of light at the same instant of time. What did you see? Did you see the lightning hit tree 1 first, hit tree 2 first, or hit them both at the same instant of time? Explain.c. In the scenario of part b, were the lightning strikes simultaneous?Explain.

A rocket with a proper length of 1500 m moves at a speed of 0.87c directly away from an observer on earth. an astronaut standing at the centre of the rocket fires two electrons at a speed 0.99c through a vacuum pipe. One electron is aimed toward the centre of the rocket, the other toward the rear. a. In the astronaut's frame, calculate the time interval between the electron reaching the front of the rocket and the other electron reaching the rear. b. In the Earth observer's frame, calculate the length of the rocket, and the speed of the two electrons moving towards the front and the rear of the rocket.

In 2010, a 20-year-old astronaut leaves her twin on earth and goes on a rocket to explore the galaxy. The rocket moves at 2.9 x 108 m/s during the voyage. It returns to earth in the year 2040.              a. Using relativity, calculate the age of the returning astronaut.       b. Find the length of the rocket in the earth’s frame of reference when it is moving, given that the rest length is 120  m. Assume you are a stationary observer viewing the rocket from the side.

The length of a rod seems shortest to an observer when it moves in a specific direction. What change would he observe when the direction of rod changes by 900? O A. The rod becomes even smaller B. The length of the rod increases O C. The length of the rod remains the same D. The rod has the length equal to its proper length O E. The length of the rod doubles