An earthling sits on a bench in a park eating a sandwich

PHYSICS · Multi-part · A Level · Physics · Turning points in physics · Turning points in physics

Problem

An earthling sits on a bench in a park eating a sandwich. It takes him 5 min to finish it according to his watch. He is being monitored by planet Zenga invaders who are passing earth at a speed of 0.90c0.90c . (1) Calculate how long the aliens reckon it takes an earthling to eat a sandwich. (2) The aliens in the spacecraft get hungry and start eating their sandwiches. It takes a Zengan 5 min to eat her sandwich according to Zengan clocks. They are actually being observed by earthlings as they fly over earth. Calculate how long it takes a Zengan to eat a sandwich according to earth clocks.

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