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In my trigonometry class, we were assigned a problem on Angular and Linear Velocity.

Here's the excerpt:
This reflecting telescope is deployed in low-earth orbit (600km) with each orbit lasting 95min.
If the radius of the Earth is 6370km, what are the angular and linear velocity of the Hubble?

Please help, I don't know how to find the velocities for this problem and which formulas to use!

User Timberman
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1 Answer

5 votes

1) 0.0011 rad/s

2) 7667 m/s

Step-by-step explanation:

1)

The angular velocity of an object in circular motion is equal to the rate of change of its angular position. Mathematically:


\omega=(\theta)/(t)

where


\theta is the angular displacement of the object

t is the time elapsed


\omega is the angular velocity

In this problem, the Hubble telescope completes an entire orbit in 95 minutes. The angle covered in one entire orbit is


\theta=2\pi rad

And the time taken is


t=95 min \cdot 60 =5700 s

Therefore, the angular velocity of the telescope is


\omega=(2\pi)/(5700)=0.0011 rad/s

2)

For an object in circular motion, the relationship between angular velocity and linear velocity is given by the equation


v=\omega r

where

v is the linear velocity


\omega is the angular velocity

r is the radius of the circular orbit

In this problem:


\omega=0.0011 rad/s is the angular velocity of the Hubble telescope

The telescope is at an altitude of

h = 600 km

over the Earth's surface, which has a radius of

R = 6370 km

So the actual radius of the Hubble's orbit is


r=R+h=6370+600=6970 km = 6.97\cdot 10^6 m

Therefore, the linear velocity of the telescope is:


v=\omega r=(0.0011)(6.97\cdot 10^6)=7667 m/s

User John Deighan
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7.2k points