Anonymous
Anonymous asked in Science & MathematicsPhysics · 1 decade ago

# A rocket moves through outer space at 11,000 m/s. At this rate, how much time would be required to travel the?

A rocket moves through outer space at 11,000 m/s. At this rate, how much time would be required to travel the distance from Earth to the Moon, which is 380,000 km? Give your answer in hours.

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• 1 decade ago

Ok, we're traveling 11,000 meters per second. The distance from the Earth to the moon is 380,000 km, or 380,000,000 meters. Divide 380,000,000 by 11,000 to give how many seconds it would take to travel: approximately 34545 seconds. There are 60 seconds in a minute, so divide 34545 by 60 to give how many minutes it would take to travel: approximately 575.75. There are 60 minutes in an hour, so divide 575.75 by 60 to give how many hours it would take to travel: approximately 10 hours.

(I've rounded several times in here, so you may want to calculate yourself).

• Anonymous

Insufficient data. You must specify the location of the rocket and its direction of travel, and also define the coordinate system in which you specify those parameters.

I shall assume you are reducing this to a one-dimensional problem, with the rocket just leaving the atmosphere and moving straight up on a line between the centers of Earth and moon. You are probably pretending that this is an inertial reference frame, despite the fact that the Earth and moon are orbiting about their mutual combined center of gravity.

The escape velocity from Earth is 11.2 km/sec, so without doing any calculating, I can say it probably doesn't have enough velocity to get past the L1 point, where the gravity of Earth and moon are equal.

To properly solve this oversimplified problem, you must apply Newton's universal law of gravitation, for both the Earth and the moon, to the position of the rocket relative to the chosen coordinate system.

Before doing that, you might want to calculate the energy needed to reach L1, and compare it to the rocket's initial energy to find out if the rocket can reach the moon, at all.

I won't waste my time doing the math until the problem is properly defined.

• Anonymous