Sideways Icicles

Icicles on a roof growing sideways because of prevailing wind currents demonstrates that the applied wind force partially overcomes the gravitational force downward.
 

• What forces are involved in the direction of the icicles?

• How long were the forces affecting the icicles? 
• Why did the phenomenon occur here but not elsewhere?

Students could:

• Complete a notice and wonder activity using the photos. Enlarge the phenomenon photo and zoom in on the icicles for a closer look or to measure angles.
• To focus on forces, use the Sideways Icicles Video clip showing the wind pattern on the building. 

• Wonderopolis | How Are Icicles Formed: This page, written for students, describes how icicles are formed.
• Kinematics in Two Dimensions | An Introduction: This lesson explains how motion can be described as made up of vertical and horizontal components. It also features links to other resources, and is suitable for teacher background or a physics class.
• The Physics Classroom | Addition of Forces: This article explains the process of adding vectors to find the net force. It also features links to other resources, and is suitable for teacher background or a physics class.
• The Physics Classroom  Vector Addition Interactive: This lesson contains teaching notes and a link to an interactive to help teach addition of vectors. Students can insert the vectors involved and it will give the resultant magnitude and angle.
• Colossal | Spectacular Ice Formations Atop a Windswept Mountain in Slovenia: Photographed by Marko Korosec the extreme conditions of humidity, freezing temperatures, and high wind created ice formations that are nearly horizontal.