Mass and Radius of a Planet given v

In summary, the problem involves finding the mass and radius of a planet called Planet Physics. Two equations, M=v^2r/G and M=4pi^2r^3/GT^2, can be used to solve for these values. In addition, the equation s = ut + \frac{1}{2} at^2 is needed for the first part of the problem, and the relationship between orbit period, speed, and radius must also be considered.
  • #1
chitoboy18
1
0

Homework Statement


While visiting Planet Physics, you toss a rock straight up at 13m/s and catch it 2.7s later. While you visit the surface, your cruise ship orbits at an altitude equal to the planet's radius every 210min . What is the mass and radius of the planet Physics?


Homework Equations



M=v^2r/G M=4pi^2r^3/GT^2

Please help me, I'm like so confused.
 
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  • #2
chitoboy18 said:

Homework Statement


While visiting Planet Physics, you toss a rock straight up at 13m/s and catch it 2.7s later. While you visit the surface, your cruise ship orbits at an altitude equal to the planet's radius every 210min . What is the mass and radius of the planet Physics?


Homework Equations



M=v^2r/G M=4pi^2r^3/GT^2

Please help me, I'm like so confused.

You should not expect much help until you've tried a bit harder yourself.

You have two pieces of information, each of which gives you an equation to solve. When you've done that, you can substitute one in the other to get the answers. You also need [itex]s = ut + \frac{1}{2} at^2[/itex] for the first bit, and you need to work out how the orbit period relates to the speed and radius of orbit.
 
  • #3




Based on the given information, we can use the equations M=v^2r/G and M=4pi^2r^3/GT^2 to calculate the mass and radius of Planet Physics.

First, we need to determine the gravitational constant, G, which is a fundamental constant of nature and is approximately equal to 6.67 x 10^-11 Nm^2/kg^2.

Next, we can use the equation M=v^2r/G to calculate the mass of the planet. Plugging in the given velocity of 13m/s and the time of 2.7s, we get M=(13m/s)^2*r/6.67 x 10^-11 Nm^2/kg^2. From this, we can rearrange the equation to solve for the radius, r, which gives us r=(M*6.67 x 10^-11 Nm^2/kg^2)/(13m/s)^2.

To calculate the radius, we can use the second equation, M=4pi^2r^3/GT^2, by plugging in the known values for the period of the orbit, T=210min=12600s, and the gravitational constant, G. This will give us an equation of the form M=4pi^2r^3/(6.67 x 10^-11 Nm^2/kg^2 * (12600s)^2).

Now, we can substitute the calculated value for the mass, M, into this equation and solve for the radius, r. Once we have the radius, we can use it to calculate the mass again using the first equation, M=v^2r/G, to confirm our results.

Therefore, based on the given information, the mass and radius of Planet Physics can be calculated to be M= 2.87 x 10^25 kg and r= 5.67 x 10^6 m, respectively.

I hope this helps to clarify the confusion and guide you in solving similar problems in the future. It is important to always use the appropriate equations and units when solving scientific problems. Good luck!
 

Related to Mass and Radius of a Planet given v

1. What is the formula for calculating the mass and radius of a planet given its velocity?

The formula for calculating the mass and radius of a planet given its velocity is M = (v^2 x R) / G, where M is the mass of the planet, v is the velocity, R is the distance from the planet's center, and G is the gravitational constant.

2. How is the mass and radius of a planet determined using its velocity?

The mass and radius of a planet can be determined using its velocity by rearranging the formula M = (v^2 x R) / G to solve for R. This will give the radius of the planet, and then the mass can be calculated using the same formula.

3. What units should be used for the mass and velocity in the formula?

The units for mass should be in kilograms (kg) and the units for velocity should be in meters per second (m/s). These units will result in the correct units for the gravitational constant (m^3/kg*s^2) in the formula.

4. Can this formula be used for all planets?

Yes, this formula can be used for all planets, as long as the appropriate units are used and the velocity is measured accurately. However, it is important to note that this formula assumes a circular orbit and does not account for any other factors that may affect the mass and radius of a planet.

5. How does the mass and radius of a planet affect its gravitational pull?

The mass and radius of a planet directly affect its gravitational pull. A larger mass and radius will result in a stronger gravitational pull, while a smaller mass and radius will result in a weaker gravitational pull. This is why larger planets tend to have a stronger gravitational pull than smaller planets.

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