超難數學題請教

👨🏻‍🏫 學術台數學

chunwangko

2007-05-21 7:04 pm

The LDEF satellite (Long Duration Exposure Facility) orbited Earth for over five years during the 1980's. Among other things, it measured the flux of dust particles that impact the Earth's upper atmosphere. The material in this dust eventually settles on Earth's surface. If the measured flux was 2.03 x 10-12 g/m2/sec (grams per square meter per second), how much mass is added to the entire Earth during the course of a year?

更新1:

Assume a radius of 6625 km for the upper atmosphere and a year of 365 days of 24 hours each. Also, please limit your answer to three significant figures. Note that you must also give the correct units for your answer!

回答 (3)

魏王將張遼

2007-05-21 7:23 pm

✔ 最佳答案

First of all, we have to find out the surface area of the earth in m2 as follows:
Radius of earth in m: 6.625 × 106 m
Surface of earth in m2: 4π × (6.625 × 106)2 = 5.515 × 1014 m2
Also, in a year, there are: 365 × 24 × 3600 = 31536000 seconds
Therefore, the mass increase in 1 year on the earth is:
2.03 × 10-12 × 5.515 × 1014 × 31536000
= 3.53 × 1010 g or 3.53 × 107 kg

參考: My Maths knowledge

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11year old

2007-05-21 9:06 pm

First of all, we have to find out the surface area of the earth in m2 as follows:

Radius of earth in m: 6.625 × 106 m

Surface of earth in m2: 4π × (6.625 × 106)2 = 5.515 × 1014 m2

Also, in a year, there are: 365 × 24 × 3600 = 31536000 seconds

Therefore, the mass increase in 1 year on the earth is:

2.03 × 10-12 × 5.515 × 1014 × 31536000

= 3.53 × 1010 g or 3.53 × 107 kg

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hok ming

2007-05-21 7:11 pm

85476

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