Rotation around fixed axis (robot arm), dynamics

[Mech_LS24]

Homework Statement

The robot arm is driven by two hydraulic cilinders A and B which brings point D rotates CW. The gear in point D has a angular velocity of 5 rad/s. Calculate the velocity and acceleration of the part in point C.

Relevant Equations

Velocity = angular velocity * radius
Acceleration = angular velocity^2 * radius

Hello,

Given the figure below, and the following statement:
"The robot arm is driven by two hydraulic cilinders A and B which brings point D rotates CW. The gear in point D has a angular velocity of 5 rad/s. Calculate the velocity and acceleration of the part in point C."

First I determined the distance from point D to C as rc/d, this distance is used for the formula's. The answer doesn't correspond, what am I missing here??

Like to here! :)

 

[Lnewqban]

The 0,9 m given dimension is irrelevant for the proper answers.
The radius to consider is the one perpendicular to the axis of rotation of the gear, arm and part.

Regarding acceleration, please see:
http://hyperphysics.phy-astr.gsu.edu/hbase/rotq.html

 

[Mech_LS24]

Thanks @Lnewqban . Found the solution :)

 

[Mech_LS24]

@Lnewqban , just to be sure, could you verify the sketch below? I draw the velocity and acceleration vectors acting on point C, where V actually goes 'into' the paper.

 

[Lnewqban]

If I understand it correctly, I believe that vector V should be pointing out of the paper, as the rotation of the gear has been said to be clockwise.
The rest of the diagram seems to be correct.

 

[Mech_LS24]

You are right, thanks!