Calculating Maximum Deceleration of Re-entry Capsule

AI Thread Summary
The discussion revolves around calculating the maximum deceleration of a re-entry capsule returning to Earth, given a re-entry velocity of 7.4 km/s and a flight-path angle of 10 degrees. Participants are attempting to use the formula a max = V^2 re-entry b sin y/ 2e, but are encountering discrepancies in their calculations. One user consistently arrives at an incorrect high value of 9.298x10^10, while another suggests that the atmospheric scale height and the base of the natural logarithm are being misapplied. Clarifications indicate that the BC number pertains to a subsequent part of the problem and that proper division and multiplication by e are crucial for accurate results. The conversation highlights the importance of careful calculation and understanding of the formula components.
spacemike1
Messages
5
Reaction score
0

Homework Statement




Contact lenses being manufactured in space are returned in a re-entry capsule to Earth for distribution and sale. If the re-entry velocity is 7.4km/s and the re-entry flight-path angle is 10 degrees, determine the maximum deceleration it will experience and at what altitude? The capsule’s BC is 1000 kg/m^2

Homework Equations



a max = V^2 re-entry b sin y/ 2e


The Attempt at a Solution



a max = 7400m/s^2 (0.000139m^-1 sin(10)) / 2(2.7182)

the answer should be 24.813 , I keep getting a very high number of 9.298x10^10 ... why am I so off?

where .000139m^-1 is the atmospheric scale height and 2.7182 is the base of the natural logarithm.
 
Physics news on Phys.org
When I run the same numbers I get 243.122 m/s^2

Where does the BC number figure into the problem?
 
the BC number is actually for the second part of the question. You got closer to me. I tried my calcs again and still getting the same off-base number. I've plugged it into the calculator just like this.

7400^2 (0.000139m^-1 sin(10)) / 2(2.7182) and get 9.298x10^10
 
You apparently are dividing by 0.000139m^-1.
 
D H said:
You apparently are dividing by 0.000139m^-1.

...and multiplying by e.
 
Thread 'Voltmeter readings for this circuit with switches'
TL;DR Summary: I would like to know the voltmeter readings on the two resistors separately in the picture in the following cases , When one of the keys is closed When both of them are opened (Knowing that the battery has negligible internal resistance) My thoughts for the first case , one of them must be 12 volt while the other is 0 The second case we'll I think both voltmeter readings should be 12 volt since they are both parallel to the battery and they involve the key within what the...
Thread 'Struggling to make relation between elastic force and height'
Hello guys this is what I tried so far. I used the UTS to calculate the force it needs when the rope tears. My idea was to make a relationship/ function that would give me the force depending on height. Yeah i couldnt find a way to solve it. I also thought about how I could use hooks law (how it was given to me in my script) with the thought of instead of having two part of a rope id have one singular rope from the middle to the top where I could find the difference in height. But the...
Back
Top