KE = half of mass times squared speed
18 = 0.5 * mass * (3m/s)^2
18 = 4.5 mass
mass = 18 / 4.5 = 4 kg
The nervous system is a complex collection of nerves and specialized cells known as neurons that transmit signals between different parts of the body.
The somatic system consists of nerves that connect the brain and spinal cord with muscles and sensory receptors in the skin.
The basic unit of the nervous system is the "nerve cell," called "neuron
Physical change 1 is the answer