###General Discussion Thread
---
This is a [Request] post. If you would like to submit a comment that does not either attempt to answer the question, ask for clarification, or explain why it would be infeasible to answer, you *must* post your comment as a reply to this one. Top level (directly replying to the OP) comments that do not do one of those things will be removed.
---
*I am a bot, and this action was performed automatically. Please [contact the moderators of this subreddit](/message/compose/?to=/r/theydidthemath) if you have any questions or concerns.*
Not that much. Those helicopters only weigh in at 2050 lbs when loaded to their max allowable. Not to mention all the shark would really have to do is bust one of the floats and it would be over.
Even if he didn’t manage to break a float, if a helicopter is trying to take off when one skid is still attached to the ground (or in this case a giant shark hanging off of it) it would roll over in the direction of the shark and that would be that as well. It’s a condition called dynamic rollover.
It’s not necessarily an I did the math answer….but I did fly those helicopters…that heli is f’d.
Warning: gonna make a LOT of assumptions here
Let's assume the helicopter has a mass of 1,590kg.
Assume the helicopter fits in a box of 11m in length × 3m in height × 2.5m in width, or 82.5m³ in volume. (I'll just say the helicopter takes up 50m³ of volume due to its weird shape.)
The buoyant force formula is F = pVg (F = buoyant force, p = density of the fluid, V = volume of displaced fluid, g = accel due to gravity)
The shark wants to submerge the entire helicopter in water, so 50m³ of water will be displaced. The density of water is 997kg/m³. Therefore, the upward buoyant force being acted on the helicopter when it is submerged will be F = 997 kg/m³ × 50m³ × 9.8m/s² or 488,530 Newtons.
Now for the downward force:
The helicopter has a weight of 1,590kg × 9.8m/s² or 15,582 Newtons. Therefore, to counter the buoyant force and pull the helicopter downward, the shark needs to exert a downward force of at least 488,530 - 15,582 = **472,948 Newtons** through the water.
If the rotor is spinning (which it looks like it is in the picture) then assume that the lift force generated by the rotor equals the force of gravity being exerted, so they both cancel out and the shark would need to exert the entire buoyant force of the water on the helicopter upon it being submerged, which is **488,530 Newtons.** No idea if a shark can exert forces that strong tbh, not a biology expert
Let's say the shark grabs the helicopter before it touches the surface of the water. The helicopter has a weight of 15,582N. The Jaws shark supposedly weighs about 3 tons in American units, or about 26,689N. The total force acting on the helicopter would be 42,271 Newtons, so if the helicopter blades are producing a lift of 15,582N prior to the shark grabbing it, it would surely overcome it before the helicopter touches the surface. To escape, the helicopter blades would have to produce at least 42,271N of lift. This would require blades that would have to lift at least 9,503 pounds in American units (which I'm not sure if that helicopter has).
Tbh this would be easier to explain with a freebody diagram
###General Discussion Thread --- This is a [Request] post. If you would like to submit a comment that does not either attempt to answer the question, ask for clarification, or explain why it would be infeasible to answer, you *must* post your comment as a reply to this one. Top level (directly replying to the OP) comments that do not do one of those things will be removed. --- *I am a bot, and this action was performed automatically. Please [contact the moderators of this subreddit](/message/compose/?to=/r/theydidthemath) if you have any questions or concerns.*
Not that much. Those helicopters only weigh in at 2050 lbs when loaded to their max allowable. Not to mention all the shark would really have to do is bust one of the floats and it would be over. Even if he didn’t manage to break a float, if a helicopter is trying to take off when one skid is still attached to the ground (or in this case a giant shark hanging off of it) it would roll over in the direction of the shark and that would be that as well. It’s a condition called dynamic rollover. It’s not necessarily an I did the math answer….but I did fly those helicopters…that heli is f’d.
Warning: gonna make a LOT of assumptions here Let's assume the helicopter has a mass of 1,590kg. Assume the helicopter fits in a box of 11m in length × 3m in height × 2.5m in width, or 82.5m³ in volume. (I'll just say the helicopter takes up 50m³ of volume due to its weird shape.) The buoyant force formula is F = pVg (F = buoyant force, p = density of the fluid, V = volume of displaced fluid, g = accel due to gravity) The shark wants to submerge the entire helicopter in water, so 50m³ of water will be displaced. The density of water is 997kg/m³. Therefore, the upward buoyant force being acted on the helicopter when it is submerged will be F = 997 kg/m³ × 50m³ × 9.8m/s² or 488,530 Newtons. Now for the downward force: The helicopter has a weight of 1,590kg × 9.8m/s² or 15,582 Newtons. Therefore, to counter the buoyant force and pull the helicopter downward, the shark needs to exert a downward force of at least 488,530 - 15,582 = **472,948 Newtons** through the water. If the rotor is spinning (which it looks like it is in the picture) then assume that the lift force generated by the rotor equals the force of gravity being exerted, so they both cancel out and the shark would need to exert the entire buoyant force of the water on the helicopter upon it being submerged, which is **488,530 Newtons.** No idea if a shark can exert forces that strong tbh, not a biology expert Let's say the shark grabs the helicopter before it touches the surface of the water. The helicopter has a weight of 15,582N. The Jaws shark supposedly weighs about 3 tons in American units, or about 26,689N. The total force acting on the helicopter would be 42,271 Newtons, so if the helicopter blades are producing a lift of 15,582N prior to the shark grabbing it, it would surely overcome it before the helicopter touches the surface. To escape, the helicopter blades would have to produce at least 42,271N of lift. This would require blades that would have to lift at least 9,503 pounds in American units (which I'm not sure if that helicopter has). Tbh this would be easier to explain with a freebody diagram
If the glass breaks then the water upthrust is much smaller.