Premium Single D-Size Battery Holder with Curved Sides Physics_Alternative Energy Twenty-centimeter steel helical spring paired

Twenty-centimeter steel helical spring paired with 2kg

the shared mass isolating volume and density as the distinguishing variables across metals and polymers

well suited to demonstrating the force on a current-carrying conductor in a magnetic field

Four 153 x 76mm plates - each holding 98 iron-rod plotting compasses in a 14 x 7 matrix - assemble flat or as the faces of a cube to display 2D and 3D field-line patterns

or carried between stations

Premium Single D-Size Battery Holder with Curved Sides Physics_Alternative Energy Twenty-centimeter steel helical spring pairedCurved side single D cell holder in premium unbreakable plastic, sized so the heavier D cell stays seated when student built circuits are picked up, tilted, or carried between stations.