Many gels and colloids are thixotropic materials, exhibiting a stable form at rest but becoming fluid when agitated. Some fluids are anti-thixotropic: constant shear stress for a time causes an increase in viscosity or even solidification. Constant shear stress can be applied by shaking or mixing. Fluids which exhibit this property are usually called rheopectic. They are much less common.
Hereâs a look at what the $19.95 excludes and how it may all add up in a very consumer-unfriendly fashion: Mileage: Rack up 50 miles between pickup and drop-off, and youâre looking at an added mileage cost of $29.50 for the van (at 59 cents a mile) and $44.50 for the truck (at 89 cents a mile). (Theoretically, U-Haul arrived at these specific mileage rates so that it could charge â and advertise â the $19.95 base fee.)
At $1.74 per mile, the national average was 28Â¢ below the rate for September 2014, due partly to the fuel price decline that shaved 22Â¢ per mile off the average surcharge. The chart at left depicts national average line haul rates and fuel surcharges for vans in the past 13 months, derived from DAT RateView.