A crew on a spacecraft watches a movie that is two hours long. The spacecraft is moving at high speed through space. An Earth-based observer watching the movie screen on the spacecraft through a powerful telescope measures the duration of the movie to be two hours.

The duration of the movie is longer than 2 hrs.

Explanation:

Given:

The duration of the movie observed by the crew on the spacecraft is 2 hrs.

According to time-dilation formula:

Here, is the required time, is the original time, is the velocity of the spacecraft and is the velocity of light.

Since , so .

So the time required will be large.

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