The simplest answer: for an average-sized commercial jetliner with typical fuel and payload, the "takeoff speed" is around 130-160 knots, or about 150 to 200 miles per hour. The landing speed is more or less the same, usually a few knots slower.
The landing/takeoff speed can range from 105 knots for a light commuter jet to nearly 200 knots for the Concorde.
In reality, many factors affect the speed at which the pilot pulls back on the flight yoke (called VR or "rotation" speed) and the speed at which the aircraft can safely leave the ground. The minimum takeoff speed is typically at least 1.3 times the speed at which it is moving quickly enough to actually generate lift (called "VS"). The variables include aircraft weight (more weight requires a faster takeoff speed), temperature, airport elevation, humidity, and degree of flaps (up to a point, increased flaps create greater lift in the wings and may allow a slower takeoff speed).
Therefore, in order to fly the aircraft as safely as possible, numerous speeds including VR (rotation speed), V1 (continue takeoff even with one engine out), V2 (safety climbing speed with one engine out) and VREF (touchdown speed) must be computed in advance. On most modern-day airliners, the cockpit is supplied with a Flight Management System in which pilots can enter weight and flap conditions and the system will compute several speeds used during takeoff and landing.
This depends on the type of aeroplane. In the case of a VTOL jet the speed is actually zero.
The Vr (rotation for takeoff) speed of a Cessna 172 is around 55 kts. The final approach speed is around 60 kts. When landing pilots strive to stall the airplane at the same time that the wheels touch the ground this happens at around 50 kts.
The aeroplane takeoff is controlled by the engine speed and the elevators.
137knots as an average
They are useful for takeoff to get lift and at landing for slowing down the plane.
Flaps and stats increase lift for takeoff and slow you down, for landing.
Yes, Flaps are both used to create lift (on takeoff) and to slow the aircraft (on Landing)
"V1" is the speed at which the flight crew must either continue with the takeoff or abort the takeoff. It is the last point at which aborting is an option.
Yes, with ear buds. You cannot play it during takeoff or landing, but in flight is OK.
Yes, electronics are permitted to be used on aircraft after reaching 10,000 feet after takeoff and before landing.
150 knots
Depends on the speed of the airplane and the landing delays.