Internal energy is the total energy contained within a system, including the kinetic and potential energy of its particles. It is a measure of the system's microscopic energy, which can include the energy associated with the motion and interactions of its molecules. Changes in internal energy can occur through heat transfer or work done on or by the system.

Internal problems refer to issues or challenges that arise within an organization or individual. These problems can include conflicts between employees, lack of communication, low morale, poor leadership, or inefficient processes. Addressing internal problems is crucial for the overall health and success of the organization or individual.

Internal pain refers to physical discomfort or distress that is felt within the body, rather than on the surface. This type of pain can be caused by a variety of factors, such as injury, illness, or inflammation. It is often described as a deep, aching, or cramping sensation and can be difficult to pinpoint or describe. Internal pain can be a sign of a serious medical condition and should be evaluated by a healthcare professional.

Internal bleeding refers to the loss of blood inside the body, rather than from a visible external injury. This can occur due to trauma, such as a car accident or a fall, or from medical conditions such as ulcers, ruptured blood vessels, or certain medications. Internal bleeding can be life-threatening if not treated promptly, as it can lead to organ damage or even death. Symptoms may include dizziness, weakness, abdominal pain, and swelling, and immediate medical attention is necessary to diagnose and treat internal bleeding.

Internal controls are processes, procedures, and policies put in place by an organization to ensure the reliability of financial reporting, compliance with laws and regulations, and the effectiveness and efficiency of operations. These controls are designed to safeguard assets, prevent and detect fraud, and ensure that the organization's objectives are achieved. Internal controls also help to minimize errors, ensure accuracy in financial records, and provide assurance to stakeholders that the organization is being managed effectively. Overall, internal controls are essential for maintaining the integrity of an organization's operations and financial reporting.

Internal accounting refers to the process of collecting, analyzing, and reporting financial information within an organization to aid in decision-making, planning, and control. It involves tracking and monitoring the financial performance of the company through the use of various accounting tools and techniques. Internal accounting helps management make informed decisions, allocate resources effectively, and evaluate the overall financial health of the organization. It is different from external accounting, which focuses on reporting financial information to external stakeholders such as investors, creditors, and regulatory authorities.

Internal insulation refers to the process of insulating the interior of a building to improve its thermal efficiency and reduce energy consumption. This can be achieved by adding insulation materials to the walls, floors, and ceilings of a building. Internal insulation helps to maintain a comfortable indoor temperature, reduce heat loss, and lower heating and cooling costs. It is a common method used to upgrade the energy performance of existing buildings.

Internal tangents are lines that intersect a circle at two points from the inside of the circle. These tangents are always located within the circle and do not intersect or touch the circle's circumference. Internal tangents are important in geometry and trigonometry, as they are used to solve problems related to circles and their properties.