Work is performed on an object when an applied force causes displacement along the same vector. Measured in joules (J) or newton-meter (Nm), work is calculated by multiplying force times displacement:  \(W = \vec{F}\vec{d}\)

Tough fibrous cords of connective tissue called tendons connect muscles to the skeleton while another type of connective tissue called ligaments connect bones to other bones at joints (elbow, knee, fingers, spinal column).

The nervous system consists of the brain and spinal cord (central nervous system) and the peripheral nervous system which is the network of nerve cells (neurons) that collect and distribute signals from the central nervous system throughout the body.

The spinal cord connects the brain to the body's network of nerves. It carries impulses between all organs and the brain and controls simple reflexes.

A substance undergoes a phase transition when it moves from one state of matter to another, for example, when water freezes or boils.