Centripetal Acceleration Part II

AI Thread Summary
To find the time required for a satellite to complete one orbit at a radius of 6689 km and speed of 7723.55 m/s, the correct formula to use is v = 2πr/T. After substituting the values, the calculation yields T = 5221.57 seconds. This converts to approximately 1.51 hours. The discussion highlights the importance of using the correct radius in calculations and emphasizes the need for unit conversion.
BitterSuites
Messages
38
Reaction score
0
[SOLVED] Centripetal Acceleration Part II

Homework Statement



(From previous question) In order for a satellite to move in a stable circular orbit of radius 6689 km at a constant speed, its centripetal acceleration must be inversely proportional to the square of the radius of the orbit.

What is the speed of the satellite? The G is 6.67259e-11 and the mass of the Earth is 5.98e24kg.

The answer to this was 7723.55 m/s.

Part II:

Find the time required to complete one orbit. Answer in units of h.

Homework Equations



The book only gives one equation for T referencing orbits, which is v=2pir/T

The Attempt at a Solution



v=2pi/T
7723.55 = 2pi/T
7723.55T = 2pi
T = 2pi/7723.55
T = .000814

I think the homework system even laughed at me when I entered that answer :)
 
Physics news on Phys.org
BitterSuites said:

Homework Equations



The book only gives one equation for T referencing orbits, which is v=2pir/T
Right.

The Attempt at a Solution



v=2pi/T
Wrong.

Compare the two equations. (You left off the r.)

And don't forget to convert your answer to the desired units.
 
*sigh* I keep making really silly mistakes.

So I input the correct equation but it came out correct.

v=2pir/t
7723.55 m/s = 2pi * 6689000m/T
7723.55T = 4.20282e7
T = 5221.57 seconds

Convert to hours

5221.57/60 = 90.6928 minutes
90.6928/60 = 1.51155 hours

Thank you so much.
 
Last edited:
TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
Thread 'Variable mass system : water sprayed into a moving container'
Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...
Back
Top