I am going to Tokyo by airplane tomorrow.

This two-motored airplane is fast.

His running speed was surprisingly fast.

His running speed is really fast.

His running speed is astonishing.

His running speed is astonishing.

A twin-engine airplane can continue to fly even if one engine fails.

He was playing by folding a paper aeroplane.

When an object is in free fall, its terminal velocity is determined by the balance between gravity and air resistance.

What is the initial velocity of this object?