The Difference Between Mass and Weight

The Difference Between Mass and Weight

There is a common perception that weight and mass are basically the same thing. This video aims to tease out the difference between mass and weight by asking people what makes a car difficult to push. The standard answer is that it is difficult to push because it's heavy. But heaviness is a measure of weight, the gravitational pull of the Earth attracting the car to Earth's center. When the car is pushed on a flat road, the force of gravity does not oppose the motion. Instead the resistance felt is an indication of the car's mass which determines its inertia. Inertia is the property of matter that means it tends to resist acceleration - the greater the mass, the less the acceleration for a given amount of force.

Massachusetts Weights & Measures Department ½ ↓ Mile ←


Image by nsub1

Question by Cardinal Rule: Why do doctors measure your height and weight each time you go in?
Maybe it's just my cynical side coming through, but I think there are only two logical answers:
1) insurance companies make them do this to profile us so they can adjust premiums
2) so the doctors can charge the insurance companies for these "services" rendered

Why else would they do it? I go in for the flu, they measure my height and weight. I have a stomach ache, first thing they do is measure my height and weight. They never use the results they obtain in their diagnosis, so why bother?


Best answer:
why do they listen to your heart, take your pulse, check your temp when you go in for back pain? - it's part of a "complete physical" and by doing so, they are 1. protecting themself from liability in case you drop dead of a heart attack before you get home-- they can say yeah, I saw him, his heart rate was fine it was in the 60's and his bp was 120/65, normal temp at 97.7. That is why-- the height and weight goes along with the physical--relate this to your car care- why do they check the fluid in your windshield wipers, or ask if you need new ones when you go to get the oil change, and don't forget they always want to change the air filter and check the air in your tires and check the threads on the tires...same thing.....

Know better? Leave your own answer in the comments!

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