# Underwater thrust formula?

• IustitiaPrime
In summary, the conversation discusses determining the force needed for one object to displace another object underwater, taking into account factors such as timeframe, density, mass, and distance traveled. It is suggested to use a numerical integration approach to calculate the necessary acceleration, taking into consideration various forces such as buoyancy and drag. The collision itself may result in energy exchange or dissipation, but can be solved through a program. There is no single equation for this problem.
IustitiaPrime
I'm trying to determine the force needed for one object to displace another object underwater. Specifically, Object A strikes Object B hard enough to jettison it from the seafloor up to sea level/land, let's say the Pacific coastline. I have a timeframe in mind, density & mass of the two objects, and distance traveled, yet don't know how to apply these factors under the liquid medium of the sea and the pressures involved. I'm not asking for easy answers so much as perhaps an equation to simplify things a bit to calculate either the force required to achieve such a feat or the energy output such a collision would yield.

I'm having trouble visualizing what you are asking about. It is like underwater billiards?

If we assume that Object A strikes Object B hard enough to push it free from the seafloor with a velocity:

1) Note that velocity and speed are not the same: https://www.physicsclassroom.com/class/1DKin/Lesson-1/Speed-and-Velocity.

2) After Object B is free from the seafloor with a velocity, it is subject to forces:

2b) A drag force. Search drag force and drag coefficient for more information.
2c) Depending on the shape of Object B, there may be a lift force. Search lift coefficient for more information.
2d) Ocean currents. The lift and drag forces are functions of the object velocity relative to the local water velocity and the object shape.
2e) Acceleration force.

Since these forces sum to zero, the remaining unknown is the acceleration. Then you integrate all of the above until the object gets to wherever it gets. It's an easy numerical integration, but difficult to impossible to do it analytically. You get your answer by writing a program to solve the problem for a given Object B velocity, then iterate that velocity (both speed and direction) until you are satisfied with the answer. Then calculate the Object A velocity needed to get the Object B velocity that you found.

A collision has energy output if it sets off an explosive. Otherwise, it results in some combination of energy exchange and/or energy dissipation.

End result is there is no single equation, but it is a solvable problem.

## 1. What is the underwater thrust formula?

The underwater thrust formula is a mathematical equation used to calculate the amount of force or thrust generated by a submerged object, such as a submarine or a swimmer, moving through water. It takes into account factors such as the speed and size of the object, as well as the density and viscosity of the water.

## 2. How is the underwater thrust formula derived?

The underwater thrust formula is derived from the principles of fluid mechanics, specifically Bernoulli's principle and the Navier-Stokes equations. It also takes into account the conservation of mass and momentum in a fluid medium.

## 3. What units are used in the underwater thrust formula?

The units used in the underwater thrust formula depend on the specific variables being used. Generally, the force or thrust is measured in newtons (N), the speed in meters per second (m/s), and the size in meters (m). However, other units may be used depending on the specific application.

## 4. Can the underwater thrust formula be used for all submerged objects?

The underwater thrust formula can be used for most submerged objects, as long as they are moving at a relatively constant speed and are not significantly affected by external forces such as currents or waves. However, it may not be accurate for objects with complex shapes or irregular movements.

## 5. How accurate is the underwater thrust formula?

The accuracy of the underwater thrust formula depends on various factors, such as the accuracy of the input variables and the complexity of the object's movement. Generally, it provides a good estimate of the thrust generated by a submerged object, but it may not be completely accurate in all situations.

• Mechanics
Replies
11
Views
2K
• Classical Physics
Replies
14
Views
498
• Mechanics
Replies
1
Views
6K
• Introductory Physics Homework Help
Replies
13
Views
2K
• Mechanical Engineering
Replies
20
Views
7K
• Introductory Physics Homework Help
Replies
11
Views
2K
• Mechanics
Replies
45
Views
12K
Replies
1
Views
2K
• Classical Physics
Replies
5
Views
1K
• Classical Physics
Replies
12
Views
2K