Questions about the dynamics of a system. Currently there is a very large scope ranging from from dynamics in mechanics, vehicle and flight dynamics, to system dynamics and fluid dynamics.
Questions tagged [dynamics]
301 questions
4
votes
2 answers
Power decreases as the diameter increases
I have a question about the use of a servo motor.
I need to lift a load of $130\ kg$ with two servo motors with $13\ Nm$.
The diameter of the shaft is $Ø40\ mm$, ie, $r=\ 20mm$.
$1\ N = 1\ Kg\ *\ 1\ m/s^2$
$1\ Nm = 1\ Kg\ *\ 1\ m/s^2*\ 1\ …
LCarvalho
- 145
- 6
2
votes
0 answers
Force on suspension when hitting a step
I'm trying to calculate the magnitude and direction of the force exerted on a wheel when encountering a step. The wheel and the steps are non-deformable.
I found two different approaches:
energy approach, from which I can calculate the difference…
user2882635
- 35
- 5
2
votes
2 answers
Linearly Damped Harmonic Motion with Sliding Friction
In Problem 2/54, I have come up with a solution only one decimal place off from the books results. I am posting to see if someone can look over my solution to see if it is correct.
To begin the equation given:
a = u*g - (k/m)x
Only works in cases…
Anonymous3.1415
- 121
- 3
1
vote
1 answer
Angular acceleration of a solid bar in a specific example of a dynamic riveted link arm configuration
Determine the angular acceleration of the $CD$ bar for the situation illustrated
in the figure. The solution is $474 \; {}^c/s^2$ $counterclockwise$.
I've done the following.
$v_B = v_A + w \cdot r_{AB} \iff v_B= -3j$
$a_B = a_A + α_{AD} \cdot…
user30316
1
vote
2 answers
How to determine the linear and angular velocity of one end of a rod that is pinned on a track on each side?
I am working on trying to determine the velocity of one end of a rod that is pinned on both ends into two different tracks. One track is linear and the pinned end has known values. The other side is pinned to a circular track in which no values are…
Barrett Cloud
- 35
- 5
1
vote
2 answers
How to calculate the max torque due to angular momentum of a beam given motor specs
I have non-rigid beam attached to a gearbox and motor assembly. The gearbox outputs $1000 N \cdot m$ at the shaft. The beam is rotated at $3000 RPM$ around it's center. If the motor is switched off immediately and acts as a brake, is it possible…
david_10001
- 275
- 1
- 11
0
votes
0 answers
0
votes
0 answers
translational kinetic energy and rotational kinetic energy
In a lever system, are there translational kinetic energy and rotational kinetic energy if the center of mass is at the centroid? and If the center of mass changes?
Loy
- 1
0
votes
1 answer
How to calculate the centripetal force along a cartesian axis?
If a centrifuge without a ballast is centered on the origin of an x-y coordinate plane, and starts at the x-axis rotating with increasing velocity counter-clockwise around the origin, how can the centripetal force of this accelerating centrifuge be…
Dale
- 193
- 7
0
votes
1 answer
Lewis form factor in between teeth
I’ve got total gear ratio of 3.428 but it’s a double step up gearbox. So I have to sq root it get the ratio of the pairs which is 1.851. For the small cog I have to use a min of 18 teeth. So teeth x g = 33.326. How can I get a real gear ratio? I’m…
Efan
- 3
- 1
0
votes
2 answers
Reaction force at a pin joint for a rod that is rotating about a fixed axis
In this diagram, assuming there is no friction between the pin joint and the rod, I understand that the rod will rotate about $O$. However, let's say that the rod is released from $ \theta = 0$ and that when $ \theta = 90$ the rod is vertical at…
J.Doe
- 3
- 2
0
votes
1 answer
Proof of angular velocity identity
I've been going thru the book by Hodges and Roithmayr regarding dynamics theory and I can't seem to prove that:
I have tried using multiple substitutions, including the fact that every component of the direction cosine matrix is equal to its…
Engels Leonhardt
- 1
- 1
0
votes
1 answer
Pulley with mass dynamics question
A pulley system has mass moment of inertia of 1.4kgm^2. If 8kg block is released from rest from S=1, by using energy approach what is angular velocity at S=2? Radius of pulley is 250mm. Note S is from the pulley centre.
This is what I…
Emmanuel
- 3
- 2
0
votes
1 answer
Angular Acceleration
Need confirmation for this question please: A pulley with Radius of 90mm and a mass moment of inertia 0.28$kgm^2$ about its central axis is subjected to a torque of 50Nm about this axis. What is angular acceleration of the pulley?
Soo, I did this:…
0
votes
2 answers
Mechanics Dynamics Question
Alright so this is my question lasses and lads: a disc with a mass moment of inertia 0.125kgm^2 about its central axis is rotating at 180rad/s about the axis. What is the angular momentum of the disc about the axis?
Soo, this is what I did: $\omega…
Michaela Kkkkkk
- 11
- 2