The Weight of a Lion's Blow: Gravity vs Force

[avito009]

I came to know that a lion's blow is equivalent to a strike of a sledge hammer. A sledge hammer weighs 15 kgs. So the force of the lions blow is 15kg.

But weight is force on the object due to gravity. So here there is no gravity involved and the force is 15kg. Can we call 15 kg as the weight of lion's blow?

 

[Stephen Tashi]

An actual strike with a sledge hammer involves a mass moving with a certain velocity or a force acting for a certain distance. So I don't think the weight of a sledge hammer is a measure of a strike with it.

 

[Khashishi]

The original claim is so vague that you need more information to correctly interpret it.

 

[phinds]

I came to know ...

This is a completely inadequate statement. Where did you read this? Do you have any sense of how reliable it is? Was it actually measured, or (MUCH more likely) is it just a similie?

 

[DaveC426913]

I'm not sure it matters. Surely it's up to the OP to decide how seriously he wants to take the metaphor or assertion or whatever.

All he is asking for is how powerful the strike of a sledgehammer is. Presumably, the best we can do is provide a typical guesstimate answer.

 

[A.T.]

I came to know ...

Where did you read this?

Why read? Maybe he was hit by a lion and a sledge hammer.

 

[phinds]

I have to disagree w/ you here, Dave. He specifically says

• I came to know that a lion's blow is equivalent to a strike of a sledge hammer.
  
• A sledge hammer weighs 15 kgs.
  
• Can we call 15 kg as the weight of lion's blow?

He is clearly equating the lion's blow to the hammer in order to ask about the lion's blow, not really the hammer.

Besides, I like to be hard to get along with

 

[DarthMatter]

I think a lion's blow with full force is more likely to be in the order of magnitude of tons than of kg, if you want to compare a weight to the force of the blow.

 

[phinds]

I think a lion's blow with full force is more likely to be in the order of magnitude of tons than of kg, if you want to compare a weight to the force of the blow.

Tons? Really? That sounds unreasonably high to me, but I'm certainly open to being wrong. What do you base that on?

 

[Matterwave]

I don't know how strong a "lion's blow" is, but if you are just confused on how a measurement of mass (kg) can be used to measure a force (SI units Newtons), then the answer is strictly it can't. The measurement of force that sometimes is used is actually "kg-f" or "kilo-gram force" which is equivalent to the weight of 1 kg in the gravity of the Earth (~9.8 Newtons). This is not an SI unit of measurement.

 

[phinds]

This is interesting:

http://www.lionlamb.us/lion/lionfact.html

The fore body of the lion is very powerfully built, and has the greatest fore body strength of any cat, except possibly the tiger. This enables the lion to deliver blows with it's [sic] forepaws heavy enough to break a zebra's back.

That certainly sounds like it could be at least the equivalent of a very forceful blow w/ a 15lb sledge. But tons? I still don't think so. This is an anecdotal source by the way, so could easily be wrong.

 

[DarthMatter]

Tons? Really? That sounds unreasonably high to me, but I'm certainly open to being wrong. What do you base that on?

I saw it on TV :D (experiment at 5:50):


It's a tiger though, and I don't know how accurate their measurements/estimations were. But I was really surprised how powerful these big cats are!

 

[phinds]

I saw it on TV :D (experiment at 5:50):

It's a tiger though, and I don't know how accurate their measurements/estimations were. But I was really surprised how powerful these big cats are!

Very interesting. thanks for posting.

I think the difference between what they are saying and what I'm thinking is in what's being measured. When I hear to phrase "tons of force", I think of a force that would lift tons of weight at least a small amount, but that can't be what they mean. For example, later in that video they say that the man exerts 2,600 lbs of force, but I don't believe for a minute that if that ball was attached to a 2,600lb weight over a pulley that when he struck it downwards the 2600 lbs weight would move upwards by even a fraction of an inch.

 

[DarthMatter]

Very interesting. thanks for posting.

I think the difference between what they are saying and what I'm thinking is in what's being measured. When I hear to phrase "tons of force", I think of a force that would lift tons of weight at least a small amount, but that can't be what they mean. For example, later in that video they say that the man exerts 2,600 lbs of force, but I don't believe for a minute that if that ball was attached to a 2,600lb weight over a pulley that when he struck it downwards the 2600 lbs weight would move upwards by even a fraction of an inch.

I also find that hard to imagine. But if one assumes that the measurement is correct and means that the ball experienced a force equal to the weight of a object with a mass of 2,600 lbs (or the equivalent in Newtons) for a very short time, what else could it mean? I assumed to have gotten out of that dilemma by observing that the work done by the force is still comparatively small, therefore the displacement of the heavy object also would be barely noticeable.

 

[phinds]

I also find that hard to imagine. But if one assumes that the measurement is correct and means that the ball experienced a force equal to the weight of a object with a mass of 2,600 lbs (or the equivalent in Newtons) for a very short time, what else could it mean? I assumed to have gotten out of that dilemma by observing that the work done by the force is still comparatively small, therefore the displacement of the heavy object also would be barely noticeable.

Well, maybe. I just can't see a guy smacking something and having that raise 2,600 lbs. by ANY amount

 

[avito009]

This is energy mass equivalence. The faster the arm of the lion moves the more kinetic energy it has. Since E=Mc² the mass of the lions blow increases to equal the weight of the sledgehammer.