The stress across a surface element (yellow disk) is the force that the material on one side (top ball) exerts on the material on the other side (bottom ball), divided by the area of the surface.
Overview. The WR450F retails for $8,290, making it the sixth-most expensive 450cc 4-stroke enduro bike of 2013. It comes equipped with a 449cc engine, which is slightly larger than average for a 4-stroke motor.he WR450F retails for $8,290, making it the sixth-most expensive 450cc 4-stroke enduro bike of 2013.
The Yamaha WR450F is an off-road motorcycle made by Yamaha Motor Company. It currently has a 450 cc (27 cu in) liquid-cooled single-cylinder engine.First offered in 1998 at 400cc, it shared many components and design concepts with the YZ400F motocross model.amaha introduced the WR 400F in 1998. The 400F is a four-stroke off-road motorcycle produced for three years, beginning in 1998 and ending in 2000 (only the YZ was upgraded to 426 cc in 2000).