(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A projectile is fired from a canon at a velocity of 0.4c at an elevation angle of 30° to the X-axis. An observor is moving at a velocity of 0.1c relative to the canon along the X direction.

(a) At what angle does the observor measure the projectile to be fired?

(b) What is the projectile’s speed relative to the observor?

2. Relevant equations

3. The attempt at a solution

Am I correct in thinking that I use the same method of Lorentz vector subtraction as shown near the bottom of the linked-to webpage below?

http://www.relativitycalculator.com/addition_relativistic_velocities.shtml

i.e. the section entitled, "What, therefore, would r & θ appear to be to an observor in relatively moving S'?"

Example 1

Or does anyone suggest another (simpler?) method?

Thank you.

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# Homework Help: Lorentz Vector Subtraction

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