Thrust is a reaction force described quantitatively by Newton's third law. When a system expels or accelerates mass in one direction, the accelerated mass will cause a force of equal magnitude but opposite direction to be applied to that system.
The force applied on a surface in a direction perpendicular or normal to the surface is also called thrust. Force, and thus thrust, is measured using the International System of Units (SI) in newtons (symbol: N), and represents the amount needed to accelerate 1 kilogram of mass at the rate of 1 meter per second per second. In mechanical engineering, force orthogonal to the main load (such as in parallel helical gears) is referred to as static thrust.
I need a thrust bearing, it has to be like the one in the picture as in it needs to have a hole in the middle(a circle). However all the non 360 degrees thruster bearings I googled are not circle shaped, but I need free space, it would preferably have the same diameters as the pic but just 270...
I had an interesting idea for increasing the Specific Impulse and Thrust of a nuclear rocket engine; it's probably not practical - best case scenario 20% increase in exhaust velocity, with proportional increase in thrust, at the cost of 1.5x to 2x weight increase, and likely much lower - but I...
Homework Statement
A 400g steel block rotates on a steel table while attached to a 1.20m -long hollow tube. Compressed air fed through the tube and ejected from a nozzle on the back of the block exerts a thrust force of 4.71N perpendicular to the tube. The maximum tension the tube can...
Homework Statement
OK, this seems simple but I want to make sure I am not doing something totally wrong. The problem says: use the conservation of mass of a system of many particles to shoe that the thrust force of a rocket that ejects mass at rate \frac{dm}{dt} is equal to F=-v_e...
Homework Statement
A cylindrical tank of radius 4cm is partly filled with water.A solid metal sphere of radius 3cm is lowered into the water by means of a thin wire until it is totally immersed. Find the increase in
(i) the depth
(ii) the pressure at a point on the base
(iii) the thrust on...
Hello forum members and thank you for letting me post.
My question refers to how rocket thrust works in a vacuum. I know this question has been posted before, but I am still confused about how it works.
My understanding is that rockets do not move by pushing against air but move by pushing...
If you have a cylinder with a slightly larger diameter at one end (the intake end) Would having one ducted fan powered by it's own motor at intake end and a second ducted fan powered by it's own motor at the exhaust end produce more thrust? It seems like the already accelerated air coming from...
Hello all, this is my first post. I was wondering if any of you could point me in the direction of a source with details on propeller aircraft able to produce a T / W Ratio greater than one.
Thank You!
Why is it that aircraft engines are always (mostly?) rated in thrust whereas most other heavy equipment I can think of (e.g. ships, earthmovers, etc. ) is mostly spoken about in horsepower.
First, am I right in my observation. If so, is this merely convention? Or does it make more sense to...
Hey guys, I want to know if I have an equation on thrust correct. I figured what's the acceleration as a function of time.
You have the upward thrust = dm/dt v, assuming the mass flow rate and the gas ejection rate is constant
and the downward force = -m(t) g, where m=m(t) since it's...
I would like to get some help if possible. I am trying to determine the correct formula to calculate the velocity of the exit stream in an aircraft. I know the thrust, the velocity of the intake, inlet diameter, and air density (ρ). Thanks for any help.
George
The Question Is: The 200 g model rocket shown in the figure generates 4.0 N of thrust. It spins in a horizontal circle at the end of a 100 g rigid rod. What is its angular acceleration? Here is the picture:
http://session.masteringphysics.com/problemAsset/1073775/3/knight_Figure_13_24.jpg...
A rocket, which is in deep space and initially at rest relative to an inertial reference frame, has a mass of 59.5E5 kg, of which 7.39E5 kg is fuel. The rocket engine is then fired for 300 s, during which fuel is consumed at the rate of 480 kg/s. The speed of the exhaust products relative to the...
Hi all,
I have been searching for days (and trying many different formulas) to try and work out the force (thrust) produced by a water pump at the end of a hose (given a perfect frictionless world) and was hoping someone could help...
The following specifications are given:
Fluid...
Hi
In a demolition what is the horizontal thrust of the near buildings remain.?
that is for calculate the scaffolding to support the near buildings of a demolition.
I read somethingh of a 10 per cent of the dead weight of the walls of the building remain but I think is very conservative...
Hi all,
I built an electric paper airplane launcher and I'm trying to figure out how much force or thrust is being applied to my paper airplane when it's launched. The setup looks like this:
The discs are 124mm in diameter, are spinning at approximately 5800 RPM each, and are about...
A fuel tank contains oil of a relative density of 0.7 on one side there is a circular trap door of 1.8m in diameter. The fuel level is 1.8m above the top edge of the door calculate the thrust on the door.
I understand that for a fixed massflow the minimum amount of power required to generate a thrust is: P = Massflow * ∫v dv = massflow *0.5* [v2^2 - v1^2]
However, is it possible to produce the same thrust with less power using the Lorentz force in an electromagnetic accelerator? If so, how can...
Homework Statement
A model rocket blasts off vertically from rest at time t=0 being pushed by an engine that produces a constant thrust force F up. The engine blasts away for t seconds and then stops. Find the height y and vertical velocity that the rocket has reached by the end of the blast...
Hello All, I was wondering that what is the force/thrust we can get from 90ci/4500psi compressed air container, which are available in market for Air guns. Also how long that force will last continuously (2 min or 5 min or more) ?
For more info about the container ...
Basically I am doing work that requires me to calculate power for given thrust of a fan which is hovering.
Variables known:
diameter of fan: 0.8m, thrust output of fan: 250kg, rho=1.1455 kg/m^3 which is the density of air at 35Celcius , and eta which is the fan efficiency = 0.8
I...
Homework Statement
basically I am doing work that requires me to calculate power for given thrust of a fan which is hovering.
Homework Equations
We are given the diameter: 0.8m, thrust output of fan: 250kg, rho=1.1455 kg/m^3, and eta which is the fan efficiency = 0.8
The Attempt...
New to the forum looking for Acceleration of Space ship with thrust
The first stage of a space vehicle consumed fuel and oxidizer at the rate of 1.90 104 kg/s with an exhaust speed of 3.45 *10^3 m/s.
(a) Calculate the thrust produced by this engine.
I got 65550000 N this answer was...
Homework Statement
A 20,000 kg rocket exhausts gasses at a constant 700 kg/sec at 300 ms^-1
Deduce the thrust applied to the rocket by its engines
Homework Equations
The only equation I know is a= T- mg/m
Where T= thrust
a=acceleration
m=mass
The Attempt at a Solution
I don't...
Can someone tell me what generates more momentum, an arrow fired from a yew long bow at its peak strength or a sword thrust from a longsword and rapier too at its strongest?
Thank you.
Hi,
I have a question about working out the power to maintain equilibrium with a spring:
I attach a rocket to a horizontal spring and fire the rocket horizontally. This is done on a track or something similar. The spring will extend until the tension in the spring equals the thrust of...
Hello, I am working on a project regarding truss analysis on a plane and I need to find all the forces acting on the truss in order to produce static equilibrium (note that I have not yet taken fluid mechanics and I wanted a challenge).
From what I have found, propeller thrust is:
Thrust...
I'm having a bit of a disagreement with someone and I hope some of you can enlighten us.
It sounds rather silly but the debate is around the physics used in a video game (Batman Arkham City). In this game, the character can jump off buildings and shape his body into a downwards dive (much...
Calculate the density at which the available thrust of a jet propelled aeroplane is equal to the minimum drag for the full fuel load case. Use the simplest assumption for the variation of engine thrust with density.
Wing area, S = 29.5
Weight, W = 88000
CD,0 = 0.02
k = 0.044
Max thrust...
So I've always wondered about how the characteristics of Jets and Props differ. I've always thought of Jets as being low volume high pressure where as props of being high volume low pressure.
I have a 750cc Jet ski that uses a water pump impeller as propulsion and it accelerates very quickly...
The burned gases of a rocket engine are ejected from the rocket nozzle at a speed of 17,000 ft/sec. If the weight of gas ejected is one pound per second, find the thrust developed by the rocket.
I don't really have an equation to use here but my guess is F = M\32.2 * Ejection Velocity...
Homework Statement
A spring of modulus 80 N and natural length 60 cm compressed to a length of 35 cm. find the thrust produced.
Homework Equations
Is thrust the opposite of tension? Do we use T=-λ/initial length x (final length-initial length) ? Or do we just solve it without adding a...
A small rocket powered by high-pressure nitrogen (R = 1776 ft-lb/slug/R, gamma=1.4) is used as an attitude control device. In space, the thrust of a rocket is given by T =mVe
in lbf. Find the thrust and exit diameter of this rocket with a throat diameter of 1.0 inch if it
operates at PT =...
I'm trying to understand thrust for a real world application. I found this formula:
T= pi / 4 x D(squared) x (v+V1/2) x p x V1
Where:
T thrust [N]
D propeller diameter [m]
v velocity of incoming flow [m/s]
V1 additional velocity, acceleration by propeller [m/s]
P density of...
Everyone knows the general thrust equation:
T = {{\dot m}_i}\left[ {(1 + f){V_e} - {V_\infty }} \right] + ({P_e} - {P_\infty }){A_e}
Where mdot_i is the incoming mass flow rate, f is the fuel flow rate, and the subscripts ∞ and e represent free-stream and exit conditions, respectively...
I was told that lubricating the interface of a thrust roller and kiln tire with graphite would reduce the thrust load since the source of the load in the traction. I need some help understanding this concept.
Thanks.
I hope you all will permit a question from a non-scientist seeking some practical guidance on a vintage table saw restoration.
I have a 1930s era table saw whose 5/8" shaft spins at 4500 rpm inside a porous bronze bearing that is lubricated with SAE 20 oil.
On the motor pulley side of the...
Hi everyone.
I need to create a mechanism involving a 12" diameter horizontal tire, spinning at 3000RPM, with 2kg mass. The wheel will be attached to a spinning shaft.
The only thing, I need to support the wheel from the bottom using flat bearings of some sort, so it can spin freely...
Is there any way to calculate the thrust provided by a propeller, given only the geometry of the propeller and the windspeed.
Given:
Stationary propeller
Wind Speed = 30 m/s
Blades = 10
Propeller Geometry:
Constant Chord length (γ)
Square tip Propeller
Pitch at root = α
Pitch at...
An example of what I mean:
Suppose you had a blueprint for a chemical rocket.
You build one, and it has mass m and provides thrust x.
Suppose you scale the whole blueprint up by 1% and build another.
The volume (and therefore the mass) of each part in the rocket has increased by a factor of...
If I know fan specifications like the size, CFM etc. How can I calculate the pressure thrust or negative pressure it creates.
I am using a fan in an opening of the cabinet that pushes air outside the cabinet. And I need to know how much pressure drop it will cause on the suction side. It will...
I am building a water rocket for my physics class and I want to make my calculations as precise as possible. I want to calculate throttle, velocity, acceleration, momentum, and max height.
With that said, what should I take into account? Gravity, wind velocity, shape of cone of the rocket...
Hello!
New poster here with a problem (No, not a homework, its a tinker problem)
Basically, I've been trying to work out how much thrust would be required to lift 150kg and make it fly around (jetpack hypothetical), assuming that there is zero lift and constant thrust from the engine/s on...
I'm working with a 3000 RPM @ 0.85 Nm motor in the transaxle from a powered scooter (like for disabled/elderly people). The differential has a 67:4 (16.75) reduction, which puts the output shafts around 179 RPM @ 14.23 Nm.
I'm passing this to a 25:9 chain drive, which makes the final output...
Hi,
Can anyone help explaining the points of action of drag and thrust forces on an aeroplane in flight and also the realtionship between Lift-Drag ration and wing configuration?!
Any help would be great!
I have a problem which I cannot crack, I am currently looking into the use of a universal joints but I want to explorer other routes too.
I am working on a gearbox test rig which requires a means of transmitting a thrust (5000 N), a torque (1800 Nm) and a speed (2000 RPM) all in the same...