Everything Science Grade 12

7.2 CHAPTER 7. MECHANICAL PROPERTIES OF MATTER

Conclusions:

1. What do you observe about the relationshipbetween the applied force
   and the extension?


2. Determine the gradient (slope) of the graph.


3. Now calculate the spring constant for your spring.

See simulation: VPnni at http://www.everythingscience.co.za)

See video: VPnnz at http://www.everythingscience.co.za

Example 1: Hooke’s Law I

QUESTION

A spring is extended by7 cm by a force of 56 N.

Calculate the spring constant for this spring.

SOLUTION

F =−kx

56 =−k× 0 , 07

k =

− 56

0 , 07

=−800 N· m−^1

Example 2: Hooke’s Law II

QUESTION

A spring of length 20cmstretches to 24cm whena load of 0,6N is appliedto it.

1. Calculate the springconstant for the spring.


2. Determine the extension of the spring if a load of 0,5N is applied to it.