query: How thick is the bark of a redwood tree?
passage: Sequoia sempervirens
The coast redwood can reach 115m (377ft) tall with a trunk diameter of 9m (30ft).[10] It has a conical crown, with horizontal to slightly drooping branches. The bark can be very thick, up to 1-foot (30cm), and quite soft and fibrous, with a bright red-brown color when freshly exposed (hence the name redwood), weathering darker. The root system is composed of shallow, wide-spreading lateral roots.
passage: Acer rubrum
Red maple is a medium quality firewood, possessing less heat energy, nominally 5.4 MJ/m³ (18.7 million BTU (mbtu) per cord), than other hardwoods such as Ash: 7 MJ/m³ (24 mbtu/cord), Oak: 7 MJ/m³ (24 mbtu/cord), or Birch: 5.8 MJ/m³ (20 mbtu/cord).