# Is this Cylinder Strong Enough to Open This Door?

## Main Question or Discussion Point

I have this door that was designed to supposedly open for 180 degrees in 1 second. A Pneumatic Plunger was used to push the door. However I'm not sure if this was strong enough to open the door. Can this be counted as Partially Inelastic Collision?

DOOR:
m = 136pound
width = 40 inch
height = 80in

PLUNGER:
Working Pressure = 80psi
Bore Size = 1.5 inch
Stroke Size = 2 inch
Max speed = 6.4in/s
m = 1 lb

#### Attachments

• 7.7 KB Views: 165

Related Mechanical Engineering News on Phys.org
Baluncore
Probably not.
The outer edge of the door where the cylinder plunger strikes is 40” from the hinge axis.
For a 180° rotation in one second, the minimum plunger velocity will need to be Pi * R = 125 inch/second.
Yet your plunger is rated at only 6.5 inch/sec.

You must reduce the radius by moving the plunger closer to the hinge line.
The door must accelerate to over 125 inch/sec during the very short travel of the plunger.
The energy in the compressed air must be sufficient to accelerate the door to high angular velocity.
A door like that is capable of killing people. You are designing a man trap.

berkeman
Mentor