SO if people have to do a seven day free trial why do they have to pay before trial?

Truck traveling west on the highway experiences an acceleration to the east. what could be the cause of this acceleration

An important dimensionless parameter concerned with very high-speed flow is the mach number, defined as v/c, where v is the speed of the object such as an airplane or projectile, and c is the speed of sound in the fluid surrounding the object. for a projectile traveling at 1170 mph through air at 50 ˚f and standard atmospheric pressure, what is the value of the mach number?

The first law of thermodynamics states that heat added to a system is neither created nor destroyed but is as it changes into other forms of energy.