In a mathematical sense, the curvature is the reciprocal of the radius, so that a smaller curvature implies a large radius. A curve of large radius, as for a railway, cannot be laid out by using the radius directly. We will see how the problem of laying out a curve of large radius is solved.
In 1983, Motorola released its first commercial mobile phone, known as the Motorola DynaTAC 8000X. The handset offered 30 minutes of talk-time, six hours standby, and could store 30 phone numbers. It also cost Â£2639 ($3995). In the very early days of the mobile space handsets werenât designed with consumers in mind.
Scroll down for the answer. Answer: The first commercially available handheld cellular phone was the Motorola DynaTAC 8000x, which hit the market in 1983 and weighed in at 2 pounds. It was priced at $3,995 and offered a half-hour of talk per batter charge. It also had a catchy nickname: âthe brick.â.