To find the velocity of a satellite in a low Earth orbit, we can use the formula derived from the gravitational force and the centripetal force required for circular motion.
The velocity \( v \) of a satellite in orbit can be calculated using the formula:
\[ v = \sqrt{\frac{G m_p}{r}} \]
where:
- \( G \) is the universal gravitational constant,
- \( m_p \) is the mass of the planet (Earth in this case),
- \( r \) is the distance from the center of the planet to the satellite.
In a low Earth orbit, when the satellite is approximately 200 km above Earth's surface, the radius \( r \) would be the Earth's radius (about 6,370 km) plus the altitude of 200 km, giving us \( r \approx 6,570 \) km, or \( 6,570,000 \) meters.
Given this, the equation to use for calculating the velocity at a low Earth orbit is:
\[ v = \sqrt{\frac{G m_p}{r}} \]
Out of the options you provided, none of them explicitly show the standard form \( v = \sqrt{\frac{G m_p}{r}} \) correctly. However, you can substitute the appropriate value for \( r \) (which should be \( 7,000 \) km or in terms of meters \( 6,570,000 \) m) when working with this formula.
The best choice from your responses would be one where the radius is used correctly, typically represented as:
\[ v = \sqrt{\frac{G m_p}{7000 \text{ km}}} \]
Make sure to convert the radius (if necessary) to meters when performing calculations.