Leather would be the most durable, and waterproof.
The Briefcase kind, obviously...
"This depends on what kind of briefcase you purchase. Most of the Tumi briefcases are made out of a leather type of material, but can also have a mix of polyester."
crane
The McKlein V Series Morgan Briefcase has a brass latch.
A lawyer would probably need a briefcase contaning evidence.
A suitable briefcase would be one that keeps materials organized, easily accessible with accessories such as a phone holder, separate area for your laptop, pen case and shoulder strap for convenience. A nice briefcase can complete your image as a serious professional while providing you with organization and accessibility of needed items.
The speed of light depends on what kind of material it's traveling in.In vacuum, the speed of light is 299,792,458 meters per second.In any material, it's somewhat less than that, and it's different in every material.
Manmade material
Malleable material
The speed of light varies depending on what kind of material it's traveling through. It's fastest when in vacuum, and it's different, and slower, in air, water, alcohol, oil, glass, jello, etc.
To ground is to eliminate any kind of electrical spark from traveling to or from any kind of equiptment.
Any kind of metal is magnetic.