Mars is twice as far from the sun as is Venus. A Martian year is about three times as long as a Venusian year. Which of these two planets has the greater rotational speed in its orbit? Which planet has the greater linear speed?

Question

Mars is twice as far from the sun as is Venus.  A Martian year is about three times as long as a Venusian year.  Which of these two planets has the greater rotational speed in its orbit?  Which planet has the greater linear speed?

Nova Adams · Accepted Answer

The orbital velocity of Venus 35 kilometer/second
Orbital..............................Earth 29.8 kilometer/second
Orbital..............................Mars 24.1 kilometer/second.

Venus takes 243 days to complete one orbit; Earth takes 23 hours and 54 minutes; Mars takes 24.623 hours; and so on. Kepler's third law is expressed mathematically as P2 = a. This means that if you know a planet's period (P = the time it takes for a planet to complete one orbit around the Sun), you can also determine that planet's distance from the Sun (a = the semimajor axis of the planet's orbit). As we move outward, planets lose velocity, with Venus having the greatest of the three.

HIX Tutor · Answer

undefined Let's break it down step by step:

1. **Distance from the Sun**: 
   - Mars is twice as far from the Sun as Venus.

2. **Orbital Speed**: 
   - Planets that are closer to the Sun move faster in their orbit.
   - Since Venus is closer to the Sun than Mars, Venus has the greater **rotational speed**.

3. **Length of Years**:
   - A Martian year (one orbit around the Sun) is about three times longer than a Venusian year.
   - This means Mars takes longer to complete one orbit.

4. **Linear Speed**: 
   - Linear speed is how fast a planet moves in its orbit.
   - Even though Mars is farther, it moves slower overall because it takes longer to go around the Sun.

So, the answer is:
- **Greater rotational speed**: Venus
- **Greater linear speed**: Venus

Both speeds are greater for Venus.

Asher Cohen · Answer

undefined The greater rotational speed in its orbit is Venus. The greater linear speed is Mars.