LinkedIn Interview Question: How would you measure the wei... | Glassdoor

## Interview Question

Products Interview Mountain View, CA

# How would you measure the weight of the earth?

1

Are you kidding me? I was not a physics major, I was a business major. Analytical skills are one thing but this was crazy.

Interview Candidate on Apr 29, 2010
1

This is a very common type of question used in consulting. It is totally theoretical and just used to see how you approach a problem. You don't need to be correct. You just need to organize your thoughts and walk the interviewer through the process you would take. This is actually a lot easier because they don't ask you to make many assumptions. The question is usually, "How much does the earth weigh?"

Maraz on Apr 4, 2011
3

How would you measure the weight of the earth?

I will develop a huge scale, use a couple hundred C-17 planes and try to lift the earth up, enough to defy gravity and then I will get the accurate weight.

Chris on Aug 6, 2011
1

Such questions are called as Fermi Problems: http://en.wikipedia.org/wiki/Fermi_problem

rsingh on Sep 27, 2011
1

This is actually a market sizing question, asked to test your analytical skills.
Heres a good book to learn this
http://www.amazon.com/Ace-Your-Case-Consulting-WetFeet-com/dp/1582070091
Here's how I would break it down, make some broad assumptions
The US is roughly 3000 miles wide, 4 -5 US sized countries placed side by side would wrap around the earth once. This is the circummference of the eartth. From this you could get the radius, and then use volume of a sphere formula (4/3 pi r cubed) to get the volume.... Conversion to weight is easy from this step on

lose_lose on Jan 30, 2013
2

The question is technically incorrect. A weight of an object is defined as "a body's relative mass or the quantity of matter contained by it, giving rise to a downward force; the heaviness of a person or thing.", which means it is measured relative to a downward force. We usually talk about weight in normal daily life, because we always assume that the Earth provides that downward force; and when in space, we say objects are weightless. So, weight is a relative measure and not absolute.

So, if we are to compute the weight of the earth, we are no longer using earth itself as a source to provide the downward force. The question should be about measuring the mass of earth.

Shahin on Apr 23, 2016
0

Just think of how we measure the celestial bodies in our universe, like for example our sun, Jupiter or a black hole in a distant universe.

The usual way is to measure the gravity the object creates and that can be measured by the curvature of the light around the object.

So point a big laser from Mars and observe the curvature from the same laser. Then calculate the mass of earth.

Another option is to measure the gravity the earth has on the moon's orbit and calculate the mass Earth needs to have to realize that orbit. (assumption in here is that you know the mass of the moon).

Saïd on Mar 8, 2019