rolling balls

• spheresRound solids, all points equidistant
• marblesSmall spherical game pieces
• bowlingPin-toppling pastime
• tumblingAcrobatic rolling and flipping
• momentumProduct of mass, velocity

gravity · ramp · slope · pinball · billiards · croquet · bocce · spinning · wheels · round · smooth · clicking · clacking · trajectory · arcade · Newton's cradle · kinetic · bouncing