Question

Approximate what is the mass of the average adult in kilograms?

the average height is 2 meters, or 200cm, but I am having trouble converting.

I know that 1m= 0.001km

This answers given are:
A) 80kg
B) 500 kg
C) 1200kg

Answer 1

1 meter equals 100 centimeters

Answer 2

okay, so 200cm....... but how do you convert that to kilograms?

Answer 3

@WiseOlMoosey ?

Answer 4

Sorry I'm thinking hard on this but this reminds me of chemistry.

Answer 5

oh, alright

Answer 6

I would say 80kg but im taking a gamble.

Answer 7

See if vinnv226 says different.

Answer 8

It might help to convert to pounds, on the earth, by multiplying by acceleration due to gravity (9.8 m/s^2) to get Newtons. The answer choices then become approximately:
800 N
5000 N
12000 N
To convert to pounds you divide by about 4. So:
200 pounds
1250 pounds
3000 pounds

So the answer is 80 kg. There are a variety of ways to do this. If you didn't know these conversions off hand it would be trickier. I'm sure there are ways to do it without converting though.

Answer 9

Wow! I should gamble more often.

Answer 10

First, average height is not 2 meters, unless you are looking at a basketball team! \(2 \text{ m} * 39.37 { in}/{m} = 78.74 \text{ in} = 6'~6.74''\)

Answer 11

that's what the slideshow said that my professor game me...... height of person= 2m

Answer 12

well, I can't dispute that he might have written that, but it clearly isn't true.

Answer 13

I'm puzzled as to the context of this question: is there more information that you didn't give us? Or are you just supposed to be getting a feel for how much a kilogram is, or a meter?

Answer 14

is there a simple equation or process where i can get 80kg, I would like to know how to solve it on my own?

the question states "Approximate what is the mass of the average adult in kg" 80kg? 500kg? 1200kg?

Answer 15

On the surface of this planet, 1 kg of mass weighs about 2.2 pounds. You could then convert all of the answer choices and see that only 80 kg makes sense.

80 kg * 2.2 lb / 1 kg = 176 lb
500 kg * 2.2 lb / 1 kg = 1100 lb
1200 kg * 2.2 lb / 1 kg = 2640 lb

even with the obesity epidemic, hopefully 80 kg = 176 lbs is the clear answer :-)

Answer 16

thanks :) clearly whoever wrote these questions are not clear :)

Answer 17

Yeah, I just wasn't sure if you were only showing us part of a more interesting problem, like trying to estimate the mass of a person given volume and density or something like that. The 2m bit didn't seem to have any relevance unless you were doing some sort of calculation.

Answer 18

But if, as it appears, this is just "intro to the metric system" then you aren't really determining the average mass or height, you're just doing some unit conversions and picking the answer that matches your personal experience with how tall and heavy people are.

Answer 19

well previously i had to "approximate the height of the average adult in cm"

Answer 20

yeah it is intro to SI units

Answer 21

it's a bit tricky because the 1 kg = 2.2 lb thing is only true places where you have the same gravity as on the Earth. pounds are actually a unit of force, whereas kilograms are a unit of mass. That's what the business about converting to Newtons (the SI unit of force) was all about...

Answer 22

oh okay, well hopefully I cant get the hang of it :/

Answer 23

It's important to get a feel for SI units, it'll make your science education much easier. It's a burden that American students have to bear unfairly, due to our country's persistence on using an obsolete and stupid system of measurements. You'll get it with a little practice.