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Question 19M.2.SL.TZ1.5b.ii

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Date May 2019 Marks available [Maximum mark: 2] Reference code 19M.2.SL.TZ1.5b.ii
Level SL Paper 2 Time zone TZ1
Command term Calculate Question number b.ii Adapted from N/A
b.ii.
[Maximum mark: 2]
19M.2.SL.TZ1.5b.ii
(b.ii)

The following data for the Mars–Phobos system and the Earth–Moon system are available:

Mass of Earth = 5.97 × 1024 kg

The Earth–Moon distance is 41 times the Mars–Phobos distance.

The orbital period of the Moon is 86 times the orbital period of Phobos.

Calculate, in kg, the mass of Mars.

[2]

Markscheme

m Mars = ( R Mars R Earth ) 3 ( T Earth T M a r s ) 2 m Earth or other consistent re-arrangement ✔

6.4 × 1023 «kg» ✔

 

Examiners report

This question was challenging for candidates. The candidates who started down the correct path of using the given derived value from 5bi often simply forgot that the multiplication factors had to be squared and cubed as well as the variables.

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