Theres this question im stuck on, if anyone could help me that would be great. Ive tried atleast 10 times. Ive used the markscheme to try and help me get the answer, Ive used chatgpt, but I cant get the answer on the markscheme:

In 2015 the Messenger spacecraft crashed into the surface of the planet Mercury after four

years in orbit observing the surface of Mercury.

Messenger's orbit was highly elliptical, varying between 200 km and 15 000 km above the

surface of Mercury. Messenger completed one full orbit every 12 hours.

mass of Messenger spacecraft = 565 kg

mass of planet Mercury = 3.30 × 1023 kg

radius of planet Mercury = 2430 km

Calculate the velocity an object would have as it reached the surface of Mercury if it was

released from Messenger's maximum orbital height.

Assume the object is released from rest and that Mercury has no atmosphere.

The main thing ive tried is GPE max (so maximum distance from mercury) = gpe min (minumum distance from mercury) + KE

But im not getting 3948 m/s, which it says is the right answer

In 2015 the Messenger spacecraft crashed into the surface of the planet Mercury after four

years in orbit observing the surface of Mercury.

Messenger's orbit was highly elliptical, varying between 200 km and 15 000 km above the

surface of Mercury. Messenger completed one full orbit every 12 hours.

mass of Messenger spacecraft = 565 kg

mass of planet Mercury = 3.30 × 1023 kg

radius of planet Mercury = 2430 km

Calculate the velocity an object would have as it reached the surface of Mercury if it was

released from Messenger's maximum orbital height.

Assume the object is released from rest and that Mercury has no atmosphere.

The main thing ive tried is GPE max (so maximum distance from mercury) = gpe min (minumum distance from mercury) + KE

But im not getting 3948 m/s, which it says is the right answer

Original post by gernig

Theres this question im stuck on, if anyone could help me that would be great. Ive tried atleast 10 times. Ive used the markscheme to try and help me get the answer, Ive used chatgpt, but I cant get the answer on the markscheme:

In 2015 the Messenger spacecraft crashed into the surface of the planet Mercury after four

years in orbit observing the surface of Mercury.

Messenger's orbit was highly elliptical, varying between 200 km and 15 000 km above the

surface of Mercury. Messenger completed one full orbit every 12 hours.

mass of Messenger spacecraft = 565 kg

mass of planet Mercury = 3.30 × 1023 kg

radius of planet Mercury = 2430 km

Calculate the velocity an object would have as it reached the surface of Mercury if it was

released from Messenger's maximum orbital height.

Assume the object is released from rest and that Mercury has no atmosphere.

The main thing ive tried is GPE max (so maximum distance from mercury) = gpe min (minumum distance from mercury) + KE

But im not getting 3948 m/s, which it says is the right answer

In 2015 the Messenger spacecraft crashed into the surface of the planet Mercury after four

years in orbit observing the surface of Mercury.

Messenger's orbit was highly elliptical, varying between 200 km and 15 000 km above the

surface of Mercury. Messenger completed one full orbit every 12 hours.

mass of Messenger spacecraft = 565 kg

mass of planet Mercury = 3.30 × 1023 kg

radius of planet Mercury = 2430 km

Calculate the velocity an object would have as it reached the surface of Mercury if it was

released from Messenger's maximum orbital height.

Assume the object is released from rest and that Mercury has no atmosphere.

The main thing ive tried is GPE max (so maximum distance from mercury) = gpe min (minumum distance from mercury) + KE

But im not getting 3948 m/s, which it says is the right answer

It does sound as though you had the right idea.

It asks what velocity an object would have if dropped from the maximum orbital height of the spacecraft- you aren’t calculating the velocity of the spacecraft itself. As such, you presumably would have to pick the mass of the object as they haven’t actually specified what it is in the question.

One thing is for certain and that is irrespective of the chosen value of m, ΔEp will be the same:

Max height = 15000 km + 2430 km = 1.743 x 10^7 m

Min height = 2430 km = 2.43 x 10^6 m

Ep (max h) = GM/(1.743 x 10^7) = 1.263 x 10^6 J

Ep (min h) = GM/(2.43 x 10^6) = 9.058 x 10^6 J

ΔEp = 7.795 x 10^6 J

(Recall that G is 6.67 x 10^-11 N m^2 kg^-2 and M = 3.30 x 10^23 kg)

Equating this to KE:

1/2 x m x v^2 = 7.795 x 10^6

v = sqrt(1.559 x 10^7 / m)

If we assume the object has a mass of 1 kg, then we do get an answer of 3948 m/s. I personally think this was a terrible question and if they wanted this answer specifically they should have told you the mass of the object itself

Original post by gernig

Theres this question im stuck on, if anyone could help me that would be great. Ive tried atleast 10 times. Ive used the markscheme to try and help me get the answer, Ive used chatgpt, but I cant get the answer on the markscheme:

In 2015 the Messenger spacecraft crashed into the surface of the planet Mercury after four

years in orbit observing the surface of Mercury.

Messenger's orbit was highly elliptical, varying between 200 km and 15 000 km above the

surface of Mercury. Messenger completed one full orbit every 12 hours.

mass of Messenger spacecraft = 565 kg

mass of planet Mercury = 3.30 × 1023 kg

radius of planet Mercury = 2430 km

Calculate the velocity an object would have as it reached the surface of Mercury if it was

released from Messenger's maximum orbital height.

Assume the object is released from rest and that Mercury has no atmosphere.

The main thing ive tried is GPE max (so maximum distance from mercury) = gpe min (minumum distance from mercury) + KE

But im not getting 3948 m/s, which it says is the right answer

In 2015 the Messenger spacecraft crashed into the surface of the planet Mercury after four

years in orbit observing the surface of Mercury.

Messenger's orbit was highly elliptical, varying between 200 km and 15 000 km above the

surface of Mercury. Messenger completed one full orbit every 12 hours.

mass of Messenger spacecraft = 565 kg

mass of planet Mercury = 3.30 × 1023 kg

radius of planet Mercury = 2430 km

Calculate the velocity an object would have as it reached the surface of Mercury if it was

released from Messenger's maximum orbital height.

Assume the object is released from rest and that Mercury has no atmosphere.

The main thing ive tried is GPE max (so maximum distance from mercury) = gpe min (minumum distance from mercury) + KE

But im not getting 3948 m/s, which it says is the right answer

You apply the conservation of energy to solve a different question imo.

The conservation of energy for this question should be

GPE (maximum distance from mercury) = GPE (at the surface of mercury) + KE (at the surface of mercury)

Note that you don’t need the mass of the Messenger.

Original post by UtterlyUseless69

It does sound as though you had the right idea.

It asks what velocity an object would have if dropped from the maximum orbital height of the spacecraft- you aren’t calculating the velocity of the spacecraft itself. As such, you presumably would have to pick the mass of the object as they haven’t actually specified what it is in the question.

One thing is for certain and that is irrespective of the chosen value of m, ΔEp will be the same:

Max height = 15000 km + 2430 km = 1.743 x 10^7 m

Min height = 2430 km = 2.43 x 10^6 m

Ep (max h) = GM/(1.743 x 10^7) = 1.263 x 10^6 J

Ep (min h) = GM/(2.43 x 10^6) = 9.058 x 10^6 J

ΔEp = 7.795 x 10^6 J

(Recall that G is 6.67 x 10^-11 N m^2 kg^-2 and M = 3.30 x 10^23 kg)

Equating this to KE:

1/2 x m x v^2 = 7.795 x 10^6

v = sqrt(1.559 x 10^7 / m)

If we assume the object has a mass of 1 kg, then we do get an answer of 3948 m/s. I personally think this was a terrible question and if they wanted this answer specifically they should have told you the mass of the object itself

It asks what velocity an object would have if dropped from the maximum orbital height of the spacecraft- you aren’t calculating the velocity of the spacecraft itself. As such, you presumably would have to pick the mass of the object as they haven’t actually specified what it is in the question.

One thing is for certain and that is irrespective of the chosen value of m, ΔEp will be the same:

Max height = 15000 km + 2430 km = 1.743 x 10^7 m

Min height = 2430 km = 2.43 x 10^6 m

Ep (max h) = GM/(1.743 x 10^7) = 1.263 x 10^6 J

Ep (min h) = GM/(2.43 x 10^6) = 9.058 x 10^6 J

ΔEp = 7.795 x 10^6 J

(Recall that G is 6.67 x 10^-11 N m^2 kg^-2 and M = 3.30 x 10^23 kg)

Equating this to KE:

1/2 x m x v^2 = 7.795 x 10^6

v = sqrt(1.559 x 10^7 / m)

If we assume the object has a mass of 1 kg, then we do get an answer of 3948 m/s. I personally think this was a terrible question and if they wanted this answer specifically they should have told you the mass of the object itself

I now realise this solution is flawed as I have conflated the gravitational potential with potential energy. The reason it worked is because if the assumed mass of the object is 1 kg, the expression for the potential energy is equivalent to that of the gravitational potential.

A corrected solution wherein the mass of the object is m kg is as follows:

Max height = 15000 km + 2430 km = 1.743 x 10^7 m

Min height = 2430 km = 2.43 x 10^6 m

Ep (max h) = GMm/(1.743 x 10^7) = (1.263 x 10^6)m J

Ep (min h) = GMm/(2.43 x 10^6) = (9.058 x 10^6)m J

ΔEp = (7.795 x 10^6)m J

(Recall that G is 6.67 x 10^-11 N m^2 kg^-2 and M = 3.30 x 10^23 kg)

Equating this to KE: 1/2 x m x v^2 = (7.795 x 10^6)m

v = sqrt(1.559 x 10^7) ≈ 3948 m/s

- GCSE Physics Question Help
- Edexcel A Level Physics Paper 3: 9PH0 03 - 17th June 2024 [Exam Chat]
- Physics
- Physics
- Physics edexcel igcse 2024
- Edexcel A Level Physics Paper 3: 9PH0 03 - 15th June 2023 [Exam Chat]
- A level physics question
- Physics
- Physics A Level unit 4 questions
- Edexcel GCSE Physics Paper 1 Higher (1PH0/1H) - 22nd May 2024 [Exam Chat]
- A level physics question on gravitational fields
- Help with (AQA) Thermal Physics / Electric Fields A-Level question?
- Gravitational potential is independent of mass
- Chemical engineering vs pharmacy?
- Edexcel A Level Physics Advanced Physics II 9PH0 02 - 6th June 2024 [Exam Chat]
- Object falling from r_2 to r_1
- AQA A-level Physics Paper 2 (7408/2) - 6th June 2024 [Exam Chat]
- the issac physics astronomy question
- IGCSE Edexcel Physics Paper 1 conversation
- Should I take a level AQA environmental science?

Latest

Trending

Last reply 3 weeks ago

Gravitational potential and gravitational potential energy definitions, PhysicsPhysics

3

2

Last reply 1 month ago

im taking A-Level physics but don't have the Grades for A-level mathsPhysics

3

7