Force of Glancing Blow

The force of collision between an airliner and a duck can be diminished greatly if the duck bounces off. The impact force is given by:

The impact force is reduced by the fact that the change in velocity is much less for the glancing blow. The vector addition which gives the final velocity shows that for a small angle deflection, the velocity change is small. The change in velocity may be calculated using the law of cosines. For consistency with example of a head-on inelastic collision, it will be assumed that a 600 mi/hr airplane collides with a 1 pound, 1 foot long duck. This calculation assumes an inelastic collision with collision time of1/880 second.
Assume an inelastic collision in which the velocity is reduced to percent of its original speed, representing a loss of percent of its kinetic energy. If the duck is deflected through an angle of degrees, then the average impact force would be tons, compared to an impact force of 12.1 tons for a head-on, inelastic collision.

Calculate for elastic case

Minimizing impact forceAirplane and duck collisionBig truck, small truck collision
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