# Homework Help: Engineering Dynamics - Velocity and Acceleration Analysis

1. Oct 13, 2014

### ConnorM

1. The problem statement, all variables and given/known data
Here is a picture of the problem! http://imgur.com/suJxZ0F
Also here it is in text,

Rod AB rotates with the angular velocity and acceleration clockwise as shown. Points A,B and C are pin connected. Point C is free to slide horizontally as shown in the figure at the instant shown determine

The velocity and acceleration of point B
The angular velocity and acceleration of rod BC, omegaBC, alphaBC
The acceleration of point C

length of rod AB = 0.5 m
length of rod BC = 0.8 m

2. Relevant equations
v = ωr (1)
an = ω2r (2)
at = αr (3)
vb = va + vb/a (4)
ab = aa + ab/a (5)

ωdω = αdθ (6)

3. The attempt at a solution

First I found the velocity of B as 3 m/s but using equation (1) and the angular velocity and length of the rod AB. Next I determined the normal and tangential acceleration of B by using equations (2)(3) and the angular acceleration, angular velocity, and length of rod AB. From the normal and tangential acceleration I used Pythagorean theorem to find the acceleration of point B = 18.06 m/s2. Next I got the angular velocity of BC by using equation (1) and using the length of BC as well as the velocity of B = 3.75 m/s. Next I found the angular acceleration of BC by using equation 3 and the acceleration of B and the length of BC, the angular acceleration I found was 22.575 rad/s2. I don't think I am doing this right, could somebody help me?

2. Oct 19, 2014