Labor theory of valueThe labor theory of value (LTV) is a theory of value that argues that the economic value of a good or service is determined by the total amount of "socially necessary labor" required to produce it. The LTV is usually associated with Marxian economics, although it originally appeared in the theories of earlier classical economists such as Adam Smith and David Ricardo, and later in anarchist economics. Smith saw the price of a commodity in terms of the labor that the purchaser must expend to buy it, which embodies the concept of how much labor a commodity, a tool for example, can save the purchaser.
Vehicle armourMilitary vehicles are commonly armoured (or armored; see spelling differences) to withstand the impact of shrapnel, bullets, shells, rockets, and missiles, protecting the personnel inside from enemy fire. Such vehicles include armoured fighting vehicles like tanks, aircraft, and ships. Civilian vehicles may also be armoured. These vehicles include cars used by officials (e.g., presidential limousines), reporters and others in conflict zones or where violent crime is common.
Sloped armourSloped armour is armour that is oriented neither vertically nor horizontally. Such angled armour is typically mounted on tanks and other armoured fighting vehicles (AFVs), as well as naval vessels such as battleships and cruisers. Sloping an armour plate makes it more difficult to penetrate by anti-tank weapons, such as armour-piercing shells (kinetic energy penetrators) and rockets, if they follow a more or less horizontal trajectory to their target, as is often the case. The improved protection is caused by three main effects.