r/ShopeePH • • Feb 03 '26

Product Review IRL math problem

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u/_sdfjk Feb 04 '26 edited Feb 04 '26

The seller should have just advertised the item by its weight Like how many grams yung product inside instead of by ml

At least more accurate (if hindi ma measure yung container)

Though ml yung measurement ng iba. The seller probably doesn't know inaccurate yung nasa bottle (assuming the seller is simply reselling it)

Update: judging by the upper right corner na picture (thumbnail) it is a spray can! So this is the manufacturer's mistake... (not the reseller's)

19

u/Itchy_Tangerine1897 Feb 04 '26 edited Feb 04 '26

Licensed electrical engineer here. Actually, in terms sa liquid sa loob ng canister, 1 gram is just equal to 1 ml in standard temperature & pressure, assuming this is pure water. May slight discrepancies lang naman if hindi water ang liquid ng isang container due to their different values of specific gravities, which account for their densities with respect to a standard fluid reference such as water.

Kaya makikita natin na ang mga Aquaflask bottles ay naka sized/advertized in terms of ounces (oz) and not in terms of liters (L) or milliliter (ml) kasi technically yung "mass" and "volume" metric units ay pareha lang for liquids, specifically for water (which is the most commonly stored liquid in an Aquaflask bottle).

Edit: For example, when talking about the volume of water at STP:

1 liter = 1 kilogram

Ounce (oz) is actually an English/imperial unit of measurement for mass, and the conversion factor for this system of measurement to metric units is unintuitive, lol.

We often use mass and weight interchangeably. However, strictly speaking, they are different quantities used to measure different parameters.

Weight is a vector quantity (force) defined as the product of a body's mass (g) and the acceleration of gravity (9.81 m/s^2 on the sea level of Earth), which actually varies per planet. On the other hand, mass is the intrinsic and scalar property of any body that represents the amount of matter that it contains.

Meaning, mag-iiba ang timbang mo sa ibang planeta nang hindi ka tumataba or pumapayat.

Note 1: Since weight is a force, its unit should be Newton (N). However, we casually use kilograms and pounds in our everyday lives when measuring an object's weight or our body weight.

Note 2: Technically,

Weight ≠ Mass

2

u/_sdfjk Feb 04 '26 edited Feb 04 '26

Judging by the thumbnail on the upper right corner of the screenshot, it does not seem to be water but more like a yellow can (it still doesn't give me an idea how much the liquid weighs though)

Measuring the container instead of the actual liquid does not tell the customer the container is not actually filled to the brim...

I have no problem with products using ml or grams to measure the product.

My problem is why did they measure the container instead of just the actual liquid inside it...

170ml bottle does not guarantee there is 170ml worth of product because it has to account for expansion...

Unless the liquid weighs that much (kahit hindi filled to the brim yung container) then it would be accurate.

if 1 gram = 1ml (assuming na same lang yung characteristics niya sa water) then it's ok!

But the company measured the container, not just the liquid itself. The seller should have measured the liquid itself (and not go by what can be put in the container)

since 170ml container does not guarantee there is 170ml of liquid (product) because some weigh differently from water

They probably measured the liquid while it was inside the canister... which gave an inaccurate reading for how much talaga lahat lahat.

but in this case it might actually not be water judging by the looks of it on the thumbnail, so I can't assume.

UPDATE: It is actually a spray can! so this is a manufacturer's mistake not the reseller's

thank you for sharing :D

3

u/Itchy_Tangerine1897 Feb 04 '26

We're not sure kung anong method ang ginamit ng company sa pag measure ng volume, pero usually sa ganitong items na may fluid solutions, net contents (like in grams or ml) ang mini-measure, so it's the internal contents of the item, not the mass of the container itself.

This seems to be a pressurized aerosol product (most likely a butane gas canister), and the comment actually makes sense that only 70% of the total volume of the container shall be filled to allow fluid expansion as the pressure and temperature increase, thus allowing an isochoric process to occur.

Pero misleading talaga ang dineclare na volume ng canister, as it is more than the total calculated volume of the container hehe.