Question #670
An overhead crane with a pneumatic lifting attachment can be used to lift:
Suwnica z chwytnikiem pneumatycznym może służyć do podnoszenia:
a
only ferromagnetic sheets
tylko blach ferromagnetycznych
b
only glass panes
tylko tafli szkła
c
sheets made of any material as well as glass panes
blach z dowolnego materiału jak i tafli szkła
Correct answer
d
materials with a highly porous structure
materiałów o silnie porowatej strukturze
Why?
A pneumatic lifting attachment (chwytnik pneumatyczny) holds the load using negative pressure (podciśnienie), so the material does not have to be ferromagnetic. It can lift suitable sheets and glass if the surface provides an airtight seal and the instructions permit that load. Highly porous material lets air in and makes the vacuum difficult to maintain.