Apollo spacecraft Homework Help

In summary, the Apollo 13 spacecraft had a total mass of 68,000 kilograms and was capable of producing 689 kilonewtons of thrust. It would take 98.7 seconds for the spacecraft to go from 24,000 miles per hour in one direction to 24,000 miles per hour in the other direction.
  • #1

Homework Statement

On April 11, 1970, Apollo 13 was launched at Kennedy Space Flight center, Florida LC 39A. Appollo 13 carried Astronaunts James A. Lovel, John L Swigert, and Fred W. Haise on their voyage to the moon. However, two days into the flight and 321,860 km from Earth when stirring the oxygen tanks, the Teflon-insulated wires that provided electricity to the stirrer motor were damaged, causing a large fire when electricity passed through them. The fire heated the surrounding oxygen, increasing the pressure inside the tank above its 1000 PSI limit, causing the tanks to explode. This explosion caused Apollo 13 to abandon its moon voyage and to try return back to Earth. To return to Earth, the astronaunts aboard Apollo 13 used the moon to slingshot them back to Earth. The spacecraft had a total mass 68,000 kg (including the 1715.2 kg of fuel and the 3 astronaunts) and was capable of producing 689 kN of thrust. Using this information, determine how long it would take for the Astronaunts traveling at 24,000 mph to perform an emergency burn and return to Earth traveling at 24,000 mph. In other words, how long would it take the Apollo spacecraft to go from 24,000 mph in one direction to 24,000 mph in the other direction. Note: Make time positive.

Homework Equations

(1)Fdt= mvf - mvi

dt= change in time
vf=final velocity
vi= initial velocity

(2) Fnet = dp/dt

dp= change in momentum
dt= change in time
Fnet= force

(3) p=mv


The Attempt at a Solution

I rearranged the first equation to get dt= mvf-mvi /F

Since the questions asks how long would it take the Apollo spacecraft to go from 24,000 mph in one direction to 24,000 mph in the other direction; I canceled out vf and vi and was left with:
dt= 68000kg/689kN = 98.7s
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  • #2
I haven't checked through everything yet, but a quick skim through tells me two things:

1) The question gives far too much useless info.

2) Your final maths on the last line of the attempt is wrong. You didn't allow for the k in kN so you are a factor of 1000 out.
  • #3
OK, convert mph to m/s for ease so everything is SI.

Now, remember the change in momentum is not zero. The Net momentum is zero.

The change in momentum = p = m(vf - vi).
Note: vf = negative, vi = positive. Therefore in the above equation you get p = m(vf - - vi).

Once you have that, you have the force and you have the change in momentum you can calculate the time.

I could be way off on this one, it's late and I can't get seem to think straight, but if you follow this, you get an answer. Whether or not it's reasonable I don't know. I don't do space flight, but it appears ok if those are the equations you are working with.

Give it a go.

Do you know the actual answer?

Related to Apollo spacecraft Homework Help

1. What was the purpose of the Apollo spacecraft?

The Apollo spacecraft was designed and used by NASA to carry astronauts to the moon and back. It was a crucial component of the Apollo missions, which aimed to fulfill President John F. Kennedy's goal of landing a man on the moon and returning him safely to Earth.

2. How many Apollo spacecraft were built?

A total of 17 Apollo spacecraft were built, including three that were used for unmanned tests and 14 that were used for manned missions. However, only 9 of these spacecraft were used for actual moon landings.

3. What were the main components of the Apollo spacecraft?

The Apollo spacecraft consisted of three main components: the Command Module, the Service Module, and the Lunar Module. The Command Module was the crew's living quarters and control center, the Service Module contained the propulsion system and supplies, and the Lunar Module was used for landing on the moon.

4. How did the Apollo spacecraft return to Earth?

The Apollo spacecraft used a heat shield and parachutes to safely return to Earth. The heat shield protected the spacecraft from the extreme temperatures of re-entering Earth's atmosphere, and the parachutes slowed it down for a safe splashdown in the ocean.

5. What advancements did the Apollo spacecraft bring to space exploration?

The Apollo spacecraft brought several advancements to space exploration, including the ability to land on the moon, perform spacewalks, and carry out scientific experiments on the lunar surface. It also paved the way for future space missions and contributed to our understanding of the universe.

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