ใใณใทใงใณใฎๅฑไธใใ็ฉไฝใใ้ใใซใฏใชใใ๏ผๅ้ๅบฆ \(v_0 = 0\) ใฎ่ช็ฑ่ฝไธใงใใๅฐ้ขใซ้ใใใพใงใฎๆ้ใไธใใใใฆใใใฎใงใใๆ้โ้ซใใใๆ้โ็ๅฐ้ๅบฆใใฎๆ็ฎๅ้กใซใชใใพใใ
(1) ใใณใทใงใณใฎ้ซใ \(h\)ใ(2) ๅฐ้ขใซ็ใ็ฌ้ใฎ้ใ \(v\)ใ
ใ\(v_0 = 0\)ใใ่ฆ่ฝใจใใจๅ ฌๅผ้ธๆใ่ชคใใ้ใใซใฏใชใ๏ผๅ้ๅบฆใผใญใจ่ชญใฟๆฟใใใฏใปใใคใใใใ