Online Course Support | Understanding Einstein: The Special Theory of Relativity

If the spaceship in the “faster than light?” example travels from San Francisco to St. Louis at a speed of 0.25c, how fast does the ship appear to be going to the observer in New York?

8. Question 8 If the spaceship in the “faster than light?” example travels from San Francisco to St. Louis at a speed of 0.25c, how fast does the ship appear…

Online Course Support | Understanding Einstein: The Special Theory of Relativity

Bob is moving to the right (positive x direction) in his spaceship at a velocity v (such that the value of the Lorentz factor is 2), and Alice is observing him. Each has their own lattice of clocks and measuring systems, which can be represented in two spacetime diagrams on the same plot, one for Bob’s frame of reference and one for Alice’s. Assume that the axes on Alice’s plot are at right angles to each other (horizontal and vertical) and Bob’s are at different but appropriate angles. If Alice observes a set of three flash bulbs at positions xA = 9, 13, and 24, and they all flash at tA = 7.3, which flash would occur first in Bob’s frame of reference?

5. Question 5 Bob is moving to the right (positive x direction) in his spaceship at a velocity v (such that the value of the Lorentz factor is 2), and…

Online Course Support | Understanding Einstein: The Special Theory of Relativity

If an object is moving at a constant speed of 1 meter/second to the right (positive x direction), and the units for the spacetime diagram are meters (for x) and seconds (for time), what would the object’s world line look like?

2. Question 2 If an object is moving at a constant speed of 1 meter/second to the right (positive x direction), and the units for the spacetime diagram are meters…

Online Course Support | Understanding Einstein: The Special Theory of Relativity

Consider a spacetime diagram for Alice’s frame of reference (so Alice is positioned at x = 0) where x is in units of light years and t is in units of years. Which of the following spacetime points have a lightlike interval with Alice’s spacetime position? (Mark all that are correct.)

7. Question 7 Consider a spacetime diagram for Alice’s frame of reference (so Alice is positioned at x = 0) where x is in units of light years and t…

Online Course Support | Understanding Einstein: The Special Theory of Relativity

In the “good guys vs. bad guys” example done in lecture, the good guys’ ship traveled away from the bad guys’ home planet at 0.6c after the signing of the treaty. In the frame of reference of the bad guys’ planet, where was the good guys’ ship after it had been traveling for 5 years?

9. Question 9 In the “good guys vs. bad guys” example done in lecture, the good guys’ ship traveled away from the bad guys’ home planet at 0.6c after the…

Online Course Support | Understanding Einstein: The Special Theory of Relativity

Bob is moving to the right (positive x direction) in his spaceship at a velocity v, and Alice is observing him. Each has their own lattice of clocks and measuring systems, which can be represented in two spacetime diagrams, one for Bob’s frame of reference and one for Alice’s. True or false: Bob’s world line is the line of same location given by xB = 0, whether it’s drawn on Alice’s spacetime diagram or Bob’s spacetime diagram.

4. Question 4 Bob is moving to the right (positive x direction) in his spaceship at a velocity v, and Alice is observing him. Each has their own lattice of…

Online Course Support | Understanding Einstein: The Special Theory of Relativity

On a graph where the x axis is horizontal and the y axis is at an angle of 70 degrees to the x axis, what are the lines that represent all points that have the same x value?

3. Question 3 On a graph where the x axis is horizontal and the y axis is at an angle of 70 degrees to the x axis, what are the…

Online Course Support | Understanding Einstein: The Special Theory of Relativity

In the “good guys vs. bad guys” example done in lecture, why was it concluded that the bad guys would actually not be able to build a ship that traveled faster than the speed of light?

10. Question 10 In the “good guys vs. bad guys” example done in lecture, why was it concluded that the bad guys would actually not be able to build a…

Online Course Support | Understanding Einstein: The Special Theory of Relativity

If the spaceship in the “faster than light?” example travels from San Francisco to St. Louis at a speed of 0.5c, how fast does the ship appear to be going to the observer in New York?

8. Question 8 If the spaceship in the “faster than light?” example travels from San Francisco to St. Louis at a speed of 0.5c, how fast does the ship appear…

Online Course Support | Understanding Einstein: The Special Theory of Relativity

Bob is moving to the right (positive x direction) in his spaceship at a velocity v (such that the value of the Lorentz factor is 2), and Alice is observing him. Each has their own lattice of clocks and measuring systems, which can be represented in two spacetime diagrams on the same plot, one for Bob’s frame of reference and one for Alice’s. Assume that the axes on Alice’s plot are at right angles to each other (horizontal and vertical) and Bob’s are at different but appropriate angles. If Alice observes a set of three flash bulbs at positions xA = 9, 13, and 24, and they all flash at tA = 7.3, which flash would occur last in Bob’s frame of reference?

5. Question 5 Bob is moving to the right (positive x direction) in his spaceship at a velocity v (such that the value of the Lorentz factor is 2), and…