Tag: science & technology

This is an exact duplicate of question 53985. Geostationary satellites must orbit at approximately 35,786 km above Earth's surface. This altitude allows the satellite to orbit at the same rate as Earth's rotation, appearing stationary from the ground. 36,000 km is the closest option to this value.

Boeing is the correct answer - it's the largest airplane manufacturer in North America and one of the two major aircraft manufacturers globally (alongside Airbus). Boeing is headquartered in Chicago, USA and produces commercial and military aircraft. Airbus is European, Rolls Royce is primarily an engine manufacturer, and BAE Systems is British.

Engine is the correct answer - aircraft engines (jet engines or propellers) generate thrust by pushing air backward, which propels the airplane forward according to Newton's third law. The fuselage is the main body, the tail contains control surfaces, and stabilizers provide stability but none produce thrust like engines do.

Four is the correct answer - the Boeing 747 is famously known as the 'Queen of the Skies' and has four engines mounted on its wings. This configuration was necessary for the heavy jumbo jet's payload and range requirements when first designed. Modern aircraft like the 777 use only two engines due to technological advances.

Wings & Tail is the correct answer - aircraft steering is achieved through a combination of control surfaces: ailerons on the wings control roll, while the rudder on the vertical stabilizer (tail) controls yaw. The elevators on the horizontal tail stabilizer control pitch. Together, these surfaces allow pilots to steer the aircraft in all three dimensions. Engines provide thrust but don't steer.

Aluminum is the correct answer - the majority of traditional aircraft structures are built from aluminum alloys due to their excellent strength-to-weight ratio and corrosion resistance. While modern aircraft increasingly use carbon fiber composites, aluminum remains the primary material for most commercial aircraft. Steel is too heavy for primary airframe structure.

Lift & Drag is the correct answer - both forces are essential for flight. Lift opposes gravity and keeps the aircraft airborne, generated primarily by the wings. Drag opposes forward motion and is actually necessary during landing - flaps and other devices increase drag to slow the aircraft. During takeoff, lift must exceed weight while drag must be overcome by engine thrust. Pressure differences create these forces but isn't itself the aerodynamic force.

Airbus is the correct answer - it's the largest European aircraft manufacturer and one of only two major commercial aircraft manufacturers globally alongside Boeing. Headquartered in France/with operations across Europe, Airbus produces the A320 family, A330, A350, and A380. Embraer is Brazilian, Saab is Swedish (mostly military), and Alenia is Italian.

Carbon Composites is the correct answer - carbon fiber reinforced polymer (CFRP) composites represent the latest advancement in aircraft construction, offering superior strength-to-weight ratio compared to aluminum. Modern aircraft like the Boeing 787 Dreamliner and Airbus A350 use extensive carbon composite structures. Titanium is also used but primarily for specific high-stress components like landing gear and engine parts.

Airbus A380 is the correct answer - it's the world's largest passenger airliner by capacity, carrying up to 853 passengers in a typical configuration. The double-deck, four-engine A380 was in production from 2007-2021. The Boeing 747 is smaller but was the previous largest. The A340 is a smaller Airbus wide-body, and Gripen is a fighter jet.