# Worksheet: Length Contraction

In this worksheet, we will practice calculating the change in the observed length as measured by an observer moving with a relative velocity.

**Q2: **

An observer located at the origin of an inertial frame sees the flash of a flashbulb occur at the position and at the time . The system is moving along the -direction of at a velocity of .

At what time in the system did the flash occur?

- A s
- B s
- C s
- D s
- E s

At what -position did the flash occur as measured in the system?

**Q3: **

A spaceship (A) is moving at speed with respect to another spaceship (B). Observers in A and B set their clocks so that the event at of turning on a laser in spaceship B has coordinates (0, 0, 0, 0) in A and also (0, 0, 0, 0) in B. A photon from the laser in spaceship B arrives at at in the frame of ship A.

What will be the time value at which the observer in spaceship B measures the photonβs arrival?

- A s
- B s
- C s
- D s
- E s

What displacement value will the observer in spaceship B measure for the position of the arriving photon?

**Q6: **

Spaceship A is moving at speed with respect to another spaceship B. A rod of length 2 m is laid out on the -axis in the reference frame of B from the origin to (2.00, 0.00, 0.00). What is the length of the rod as measured by an observer in the reference frame of spaceship A? Give your answer to 3 significant figures.