Circular Motion (ratio of velocities)

In summary, the conversation discusses two small planets moving in circular orbits around the same star and asks for the ratio of their speeds. The solution involves using Kepler's third law to find a starting point.
  • #1
Qualenal
1
0

Homework Statement



Two small planets are moving in circular orbits around the same star. If the radius of the orbit of planet A is 4 times the radius of the orbit of planet B, find the ratio of their speeds vA/vB.

Homework Equations



Not really sure but
v=omega*r
a(centripetal)=v^2/r
UCM T=2*pi*r/v

The Attempt at a Solution


I honestly have no idea how to do this problem. I know the answer is .5 I just want to know how to get there!
 
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  • #2
Qualenal said:

Homework Statement



Two small planets are moving in circular orbits around the same star. If the radius of the orbit of planet A is 4 times the radius of the orbit of planet B, find the ratio of their speeds vA/vB.

Homework Equations



Not really sure but
v=omega*r
a(centripetal)=v^2/r
UCM T=2*pi*r/v

The Attempt at a Solution


I honestly have no idea how to do this problem. I know the answer is .5 I just want to know how to get there!

Have a look at Kepler's third law. It may give you a starting point.
 

1. What is circular motion?

Circular motion is a type of motion in which an object moves in a circular path around a central point. This can be seen in objects such as planets orbiting around the sun or a car going around a roundabout.

2. What is the ratio of velocities in circular motion?

The ratio of velocities in circular motion is known as the angular velocity. It is the rate at which an object rotates around a central point, and is measured in radians per second.

3. How is the ratio of velocities calculated?

The ratio of velocities is calculated by dividing the distance traveled in a circular path by the time it takes to complete one full rotation. This can also be expressed as the circumference of the circle divided by the period of rotation.

4. What is the relationship between linear and angular velocity in circular motion?

The relationship between linear and angular velocity in circular motion can be expressed as v = ωr, where v is the linear velocity, ω is the angular velocity, and r is the radius of the circular path. This means that as the radius of the circle increases, the linear velocity also increases.

5. How does the ratio of velocities affect the stability of an object in circular motion?

The ratio of velocities affects the stability of an object in circular motion through centripetal force. As the angular velocity increases, the centripetal force needed to keep the object in its circular path also increases. If the centripetal force is not strong enough, the object will lose its circular motion and either slow down or fly off in a straight line.

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