Algodoo

***Scroll to the right to see the black box. Change the weight of the box to make the earthquake stronger or weaker. Higher mass is a stronger earthquake, and lower mass is a weaker earthquake. Select the springs by zooming out to either change the frequency of ground movement, or earthquake duration. For earthquake frequency, change the spring strength (top bar) to change it. A higher value means a higher frequency, and a lower value for a lower frequency. For earthquake duration, select the springs, and change the damping value. Higher damping means a lower duration, and a lower value means a longer duration. I WOULD NOT RECOMMEND GOING ABOVE 0.25!!!***