forces & elasticity

• when you apply a force to an object you may cause it to stretch, compress, or bend
• why is more than one force required to change the shape of an object?

  the object would move in the direction of the applied force, instead of changing shape
• what is elastic deformation?

  object returns to its original length when force is removed e.g. spring
• what is inelastic deformation?

  an object has been inelastically deformed if it doesnt return to its original shape and length when the force is removed
• what type of energy is stored in a spring when its stretched/compressed?

  elastic potential energy. provided the spring is not inelastically deformed, the work done on the spring and the elastic potential energy stored are equal.
• what equation would you use to calculate work done in stretching a spring

  elastic potential energy = 1/2 x spring constant x extension2
• what is Hooke's law?

  The extension of an elastic object, such as a spring, is directly proportional to the force applied, provided that the limit of proportionality is not exceeded.
• what is spring constant?

  measure of the stiffness of a spring, the larger the spring constant, the stiffer it is
• what equation would be used to calculate force, given you have force, spring constant, extension/compression?

  force ( N ) = spring constant ( N/m ) x extension/compression ( m )