# angular

1. ### How can I find the modulus of the angular acceleration?

The problem is as follows: A pulley starts spinning from rest a rotation with constant angular acceleration. After $5\,s$ a point in its periphery has an instant acceleration which makes a $53^{\circ}$ angle with its linear speed. Find the modulus of the angular acceleration (in...
2. ### How do I find the average angular velocity between two points?

The problem is as follows: In the figure from below it is shown an observer who has put himself at the center of the coordinate system. He sees an object moving in a circular trajectory. If the average speed between $A$ and $B$ is $\left ( -2\hat{i}+\hat{j} \right )\frac{m}{s}$ and its position...
3. ### How Angular Velocity of Earth is 2Ï€/T?

moment of inertia of the earth; I = \large \frac {2}{5} \normalsize MR^{2} Angular Velocity of Earth ; Ï‰ = \large \frac {2Ï€}{T} Here Earth is considered as solid sphere. I didn't understand how Angular Velocity of Earth is \large \frac {2Ï€}{T}?
4. ### How Earth maintain its same angular momentum even after sun disappears?

How Earth maintain its same angular momentum even after sun disappears ?
5. ### Why we have to add I Ï‰ to final angular momentum; Lf?

A 1 kg mass of clay, moving with a velocity of 10 m/s, strikes a stationary wheel and sticks to it. The solid wheel has a mass of 20 kg and a radius of 1m. Assuming that the wheel is set into pure rolling motion, the angular velocity of the wheel immediately after the impact is approximately...
6. ### rate of angular momentum of a point

Hi, Does anyone know how to calculate the rate of angular momentum of a point,Q? Google is not helping me right now. Thanks
7. ### Determine the angular momentum

Well finally got to the last question. I thought this one would be easy but I'm unsure. I've looked into this question. I have the mass, the velocity, and I think radius. If I manage to get the last one right that would be awesome.
8. ### Angular velocity

Can anybody help me with this please, i do not understand how to find the angular or linear velocity from this problem: A pulley has a diameter of 180mm and is turning at 300 rpm; 140mm of a belt drive is in contact with a pulley
9. ### Trouble comparing angular acceleration to linear acceleration :

I'm learning about angular velocity, momentum, etc. and how all the equations are parallel to linear equations such as velocity or momentum. However, I'm having trouble comparing angular acceleration to linear acceleration. Looking at each equation, they are not as similar as some of the...
10. ### Linear and Angular Speed?

A wheel of radius 10 inches is rotating 30Â°/sec. What is the linear speed in in/sec and the angular speed in RPM? What is the angular speed in radians/sec?
11. ### angular acceleration,torque, inertia questions

so i have some issues with a question im facing, hope you guys can clarify some details. a rotor overcomes friction with a "resistance couple" of 15Nm. the rotor is 60Kg and a radius of 0.5m, determine; A: torque required to accelerate the rotor from rest to 300rpm in 4 seconds. B...
12. ### Calculating a Radius Using 2 Points and an Angular Displacement

Thank you in advance for any and all replies. I am attempting to calculate the radius of a circle using a known linear displacement (L1-L2) and an angular displacement (X). I just cannot seem to derive an equation that will give me R even though I know that I should have sufficient information.
13. ### Angular Acceleration Calculator

What is angular acceleration? Angular acceleration is also known as rotational acceleration which is a quantitative expression for change in angular velocity of a spinning object which undergoes per unit time. angular velocity is explained in simple form as rate of change of angular velocity...
14. ### How do I construct a function s(x) that determines angular velocity??

here's the full question: A movie crew is working on a scene that involves filming a car moving at a high speed. For one perspective, a camera is positioned and fixed at a spot 50 feet from the carâ€™s path (see point C below). Construct a function s(x) that determines the speed (in radians...
15. ### angular velocity

Hi I need to find the angular velocity for a car moving at 100 km/h with a wheel radius of 35 cm V=Ï‰*r so rearranged I have Ï‰=v/r which is Ï‰=27.78(m/s)/.35(m) Ï‰=79.37 (s) ?? Have I got this right or am I way off? Thanks in advance.
16. ### Angular Velocity / Levers question help.

Hi all, new member here. I'm currently working through some of my engineering work and have been stuck on this question for the last 3 days, reading books on it and scouring the internet and having no luck at all. I will post a picture of it, if anyone has any clue and can set me in the...
17. ### Apparent angular diameter

You have a friend 6 feet high, who begins walking away from you at a rate of 5ft/sec. Write an expression relating their angular diameter "theta" to their distance "x". How do I approach this?
18. ### Obtaining angular velocity given linear velocity and center of rotation 3D

Hi, Supposed I'm given linear velocity and center of rotation in 3D. Can I obtain the angular velocity? I tried using: v = w x r v (1x3 vector) = A (3x3 matrix) * w (1x3 vector) then take the inverse of the 3x3 matrix A and w = inv A * v But the inverse of A gave an error...
19. ### Finding angular speed

A cart is traveling at 9.55 miles per hour on a cable with 8.5 diameters.Find angular speed and convert to RPM. So I know linear speed has a relationship to angular speed of v(linear speed)= radius X w(angular speed). So since we have the linear speed of 9.55 and the radius of 8.5. We plug it...
20. ### Rotation matrices and exponential map for angular momentum

Hi guys, I'm having some trouble with rotation matrices. Basically, this is the problem: Let R(na) be a matrix in SO(3), where na specifies the rotation the matrix represents. Namlely, n is the unit vector about which the rotation is performed, and a is the angle of the rotation. Let...