Initial Acceleration of a Center of Mass

by mparsons06
Tags: acceleration, initial, mass
mparsons06 is offline
Apr8-10, 12:40 PM
P: 61
1. The problem statement, all variables and given/known data

A uniform rod of length 1.25 m is attached to a frictionless pivot at one end. It is released from rest from an angle θ = 23.0 above the horizontal.

Find the magnitude of the initial acceleration of the rod's center of mass.

I keep getting the wrong answer. Please help with a push in the right direction.
Phys.Org News Partner Science news on
NASA's space station Robonaut finally getting legs
Free the seed: OSSI nurtures growing plants without patent barriers
Going nuts? Turkey looks to pistachios to heat new eco-city
Kenyi is offline
Apr8-10, 12:44 PM
P: 1
You can use the fact that the center of mass lies at 1/2 * L and that gravity grips the rod here. You can then use a simple geometric rule to find the force perpendicular to the rod, hence its initial acceleration.
jeppetrost is offline
Apr9-10, 12:27 PM
P: 88
You can calculate the torque exerted by gravity, and hence the angular acceleration of the rod. This can be related to the linear acceleration (of for instance the CoM) by the formula
[tex] \alpha D = a[/tex]
where D is the distance to the point of interest (CoM in this example)

Register to reply

Related Discussions
Velocity and Acceleration of the Center of Mass? Introductory Physics Homework 3
Conceptual Center of Mass acceleration problem Introductory Physics Homework 12
acceleration of center of mass of cart-block system Introductory Physics Homework 9
acceleration of center of mass Introductory Physics Homework 7
acceleration of center of mass Introductory Physics Homework 1