# Weight or Force of Gravity: Which is Applied to a Man Lifting a Mass?

• oreo
In summary, the mass of a object applies a downward force on the hand of the person holding it. This contact force is known as the normal force.
oreo
I have a question. Suppose a man is lifting a Mass. The mass of course pushes it down. Now what is the force the mass is applying to hand of man is it Weight or Force of gravity because weight acts on mass itself. Then what we call it precisely?

I think I understand what you are asking but I find it to be a very confusingly phrased question. Perhaps it would work if you were to look up the definitions of the terms mass, force, weight, and gravity to help clarify what you are asking.

phinds said:
I think I understand what you are asking but I find it to be a very confusingly phrased question. Perhaps it would work if you were to look up the definitions of the terms mass, force, weight, and gravity to help clarify what you are asking.
To elaborate it I would use Newtons 3rd Law
Suppose you have a mass in your hand, you are lifting it and it is in equilibrium. I am clear with the support force that is being applied by the hand at the mass. What is the force the mass is applying to hand??

The force of gravity and weight are essentially the same. Weight is an everyday word we use in our language that represents the downward force of an object due to the Earth's pull. Weight IS the force of gravity experienced by an object. The mass that is in your hand would exert a downward gravitational force on your hand. (As far as I know, physicists don't talk in terms of weight, always in terms of gravitational force).

Physicist97 said:
The force of gravity and weight are essentially the same. Weight is an everyday word we use in our language that represents the downward force of an object due to the Earth's pull. Weight IS the force of gravity experienced by an object. The mass that is in your hand would exert a downward gravitational force on your hand. (As far as I know, physicists don't talk in terms of weight, always in terms of gravitational force).
But notice weight is force something is pulled BY but it is pulling in this case

shayan haider said:
what is the force the mass is applying to hand of man is it Weight or Force of gravity
No. The force the mass applies to the hand is a contact force. Also called a mechanical or normal force.

shayan haider said:
Now what is the force the mass is applying to hand of man is it Weight or Force of gravity because weight acts on mass itself. Then what we call it precisely?

The force on the hand? Well, if we list the forces acting on the hand, we should be able to find out.

1. The weight of the man's hand (mg) acting downward.
2. The force from the man's wrist acting upward.
3. The force from the mass the hand is holding up, acting downward.

Now, it would be easy to think that number 3 is also the weight of the mass. But it's not. The magnitude of the force is equal to the weight of the mass, but, crucially, if the man were to drop his hand so that his hand and the mass accelerate downward, the force of the mass on the hand would NOT be equal to the mass's weight, but a lesser amount. This force is a contact force, the normal force, like DaleSpam said.

Drakkith said:
The force on the hand? Well, if we list the forces acting on the hand, we should be able to find out.

1. The weight of the man's hand (mg) acting downward.
2. The force from the man's wrist acting upward.
3. The force from the mass the hand is holding up, acting downward.

Now, it would be easy to think that number 3 is also the weight of the mass. But it's not. The magnitude of the force is equal to the weight of the mass, but, crucially, if the man were to drop his hand so that his hand and the mass accelerate downward, the force of the mass on the hand would NOT be equal to the mass's weight, but a lesser amount. This force is a contact force, the normal force, like DaleSpam said.
I am sure that the thing is applying force less than its weight!

shayan haider said:
I am sure that the thing is applying force less than its weight!
If the mass that you hold in your hand doesn’t accelerate, the force it applies to your hand is equal to its weight. If the mass accelerates it can be more or less in magnitude, depending on the direction of acceleration.

I think it is complete explanation. Thanks!

## 1. What is the difference between weight and force of gravity?

Weight refers to the measure of the downward force exerted on an object by the Earth's gravity. Force of gravity, on the other hand, is a type of force that attracts two objects with mass towards each other. In simple terms, weight is a type of force that is affected by gravity.

## 2. Is weight or force of gravity more important when lifting a mass?

Both weight and force of gravity are important when lifting a mass. The weight of the object being lifted is determined by its mass and the force of gravity acting upon it. So, in order to lift a mass, both weight and force of gravity must be considered.

## 3. How is the weight or force of gravity calculated?

The weight of an object can be calculated by multiplying its mass by the acceleration due to gravity (9.8 m/s²). The force of gravity can be calculated using Newton's Law of Universal Gravitation, which takes into account the masses and distance between two objects.

## 4. Why does weight or force of gravity vary on different planets?

Weight and force of gravity vary on different planets because they have different masses and sizes. The larger the mass and size of a planet, the stronger its gravitational pull will be. This means that a person's weight and the force of gravity acting upon them will be different on each planet.

## 5. Can weight or force of gravity be manipulated?

Weight and force of gravity cannot be manipulated, as they are natural forces that are determined by the mass and size of objects. However, the effects of weight and force of gravity can be counteracted using other forces, such as lifting an object with an equal and opposite force or using technology, such as anti-gravity machines.

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