# Mass and weight relationship

### Weight or Mass? The mass of an object is a fundamental property of the object; a numerical measure of The weight of an object is the force of gravity on the object and may be. The weight of an object is the force on it due to gravity. There is a relationship between weight, mass and acceleration of free-fall (weight = mass × acceleration . In common usage, the mass of an object is often referred to as its weight, though these are in . Usually, the relationship between mass and weight on Earth is highly proportional; objects that are a hundred times more massive than a one- liter.

## Mass versus weight

After all, without the huge mass that makes up planet Earth we'd have no gravity - a great way to save money on fuel as you can simply float to work, but not so great when you're trying to drink your morning espresso on your way to the office.

Weight is a form of measurement that is dependent on gravity and, unlike mass, your weight can vary depending on where you are in the universe. Weight is a pretty important measure not only to dieters the world over but also to the scientists and egg heads who design things like space shuttles and boats - opposite end of the spectrum, but it's all about perspective. But how can weight vary whilst mass has to remain constant? Scientists have defined weight using this equation: Some key points about weight The weight of an object changes based on where it is.

If you've decided to visit the moon to test out this theory then you'll find that, in a matter of hours, you will have slashed your weight by two thirds in your face, Slimming World!

Weight is a vector and its direction of pull is towards the centre of the planet you're stood on. Sorry, I did promise layman's terms: The weight of any given object can go up or down depending on the amount of gravity acting on it.

More gravity - the heavier the object. Less gravity - the lighter the object. Unlike mass, weight can be zero. The weight of a body keeps on decreasing at higher altitude where it is furthest away from the center of gravity of Earth. They are directly proportional to each other. Mass is defined as the amount of matter with which it is made up of, regardless of its configuration or any force acting on the body.

## Weight or Mass?

Weight is the computation of the force of gravity acting on a body and it depends on the value of acceleration due to the gravity of the place in which the body resides. Mass of a body being constant at any place is unaffected by the gravity whereas weight of an object is directly proportional to the value of gravity of that place.

S unit of mass is kilogram and gram respectively whereas that of weight is Newton and dyne respectively. Device used for measurement: Though the rubber comprising the balloon has a mass of only a few grams, which might be almost unnoticeable, the rubber still retains all its mass when inflated. If one were however to weigh a small wading pool that someone then entered and began floating in, they would find that the full weight of the person was being borne by the pool and, ultimately, the scale underneath the pool.

However, as noted, an object supported by a fluid is fundamentally no different from an object supported by a sling or cable—the weight has merely been transferred to another location, not made to disappear. The mass of "weightless" neutrally buoyant balloons can be better appreciated with much larger hot air balloons. Buoyancy and the resultant reduction in the downward force of objects being weighed underlies Archimedes' principlewhich states that the buoyancy force is equal to the weight of the fluid that the object displaces. If this fluid is air, the force may be small. Buoyancy effects of air on measurement[ edit ] Normally, the effect of air buoyancy on objects of normal density is too small to be of any consequence in day-to-day activities. For convenience, a standard value of buoyancy relative to stainless steel was developed for metrology work and this results in the term "conventional mass".

Since objects with precisely the same mass but with different densities displace different volumes and therefore have different buoyancies and weights, any object measured on this scale compared to a stainless steel mass standard has its conventional mass measured; that is, its true mass minus an unknown degree of buoyancy. In high-accuracy work, the volume of the article can be measured to mathematically null the effect of buoyancy. Types of scales and what they measure[ edit ] A balance-type weighing scale: Unaffected by the strength of gravity. Load-cell based bathroom scale: Affected by the strength of gravity. This is because balances "dual-pan" mass comparators compare the gravitational force exerted on the person on the platform with that on the sliding counterweights on the beams; gravity is the force-generating mechanism that allows the needle to diverge from the "balanced" null point.

### What Is The Difference Between Mass And Weight?

These balances could be moved from Earth's equator to the poles and give exactly the same measurement, i. But if you step onto spring-based or digital load cell -based scales single-pan devicesyou are having your weight gravitational force measured; and variations in the strength of the gravitational field affect the reading. In practice, when such scales are used in commerce or hospitals, they are often adjusted on-site and certified on that basis, so that the mass they measure, expressed in pounds or kilograms, is at the desired level of accuracy.

NIST Handbook states: The weight of an object is a measure of the force exerted on the object by gravity, or the force needed to support it. The pull of gravity on the earth gives an object a downward acceleration of about 9.

In trade and commerce and everyday use, the term "weight" is often used as a synonym for "mass.