2/49 on its takeoff roll, the airplane starts from rest and accelerates according to a=a0−kv2, where a0 is the constant acceleration resulting from the engine thrust and −kv2 is the acceleration due to aerodynamic drag. if a0=2 m/s2, k=0.00004 m−1, and v is in meters per second, determine the design length of runway required for the airplane to reach the takeoff speed of 250 km/h if the drag term is (a) excluded and (b) included.

The length of the runway required when (a) drag force is not taken into account is 1.21 km, (b) the drag force is taken into account is 1.33 km.

(a) Express the take off speed in m/s.

Use the equation of motion,

Substitute 0 m/s for u, 69.44 m/s for v and 2m/s²for a.

The length of the runway required when no drag force acts on the airplane is 1.21 km.

(b) When the drag force acts, the acceleration is given by,

calculate the acceleration by substituting 2 m/s² for a₀, 0.00004/m for k and 69.44 m/s for v.

Use the equation of motion,

Substitute 0 m/s for u, 69.44 m/s for v and 1.807m/s²for a.

When the acceleration of the plane is reduced by air drag, the length of the runway needed is 1.33 km.

electromagnetic shielding is the practice of reducing the electromagnetic field in a space by blocking the field with barriers made of conductive or magnetic materials. shielding is typically applied to enclosures to isolate electrical devices from their surroundings, and to cables to isolate wires from the environment through which the cable runs. electromagnetic shielding that blocks radio frequency electromagnetic radiation is also known as rf shielding.

the shielding can reduce the coupling of radio waves, electromagnetic fields and electrostatic fields. a conductive enclosure used to block electrostatic fields is also known as a faraday cage. the amount of reduction depends very much upon the material used, its thickness, the size of the shielded volume and the frequency of the fields of interest and the size, shape and orientation of apertures in a shield to an incident electromagnetic

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