In this chapter we introduce the concepts of work, energy and power. We define kinetic energy, gravitational potential energy, and the potential energy stored in a compressed or stretched spring. If all forces are conservative, the mechanical energy of an isolated system is constant. If non-conservative forces are present, we use the work-energy theorem to equate the work done by the non-conservative forces and the change in mechanical energy.
TUYỂN TẬP 20 ĐỀ THI KHẢO SÁT HỌC SINH GIỎI MÔN TIẾNG ANH LỚP 6 NĂM 2020 (CÓ Đ...
ກົນລະສາດ2 ງານ ແລະ ພະລັງງານ ( Work and Energy)
1. Pem PHAKVISETH
General Physics Pem Pvs: 1
F
s
(ใช้ Fcos เพราะอยู่ในแนวขนานกับ s )
F
s
F
s
W = F s
F
s
W = 0 W = Fcos s
F cos
F sin
ຍ຺ຈີ 5 ຄາຌຖະຑະຖັຄຄາຌ
5.1. ຄາຌ
ຄາຌ ຽຎັຌຏ຺ຌດໃາຄໜໃ ຄຽຆໃຄຽກີຈາກກາຌບບກປຄຄາຌກະາຉໃທັຈຊຸຖໄທຽປັຈເນໄທັຈຊຸຽໃບຌີໃ ແຎ
ຉາຓຌທປຄຌ ັໄຌ.
ຽປ຺າຘາຓາຈນາຂະໜາຈຂບຄຄາຌແຈໄາກຏ຺ຌູຌຖະນທໃາຄຂະໜາຈປຄກ ັຍກ ັຍກາຌກະ ັຈຉາຓຌທ
ປຄ ຂຼຌຽຎັຌຘູຈະແຈໄ
W = F.s
ຽຓໃບ F ຓໃຌປຄ ( N )
S ຓໃຌກາຌກະ ັຈຉາຓຌທປຄຌ ັໄຌ (m)
W ຓໃຌຄາຌ (N, m , J )
ໝາງຽນຈ : ຊໄາຈຂບຄປຄຓີຈຈຼທກ ັຍຈຂບຄກາຌກະ ັຈ ຉໄບຄຌໃາປຄ (F) ຽຎັຌໃາຍທກ
ຊໄາຈຂບຄປຄຓີຈກ ຺ຄກ ັຌຂໄາຓກ ັຍຈຂບຄກາຌກະ ັຈຉໄບຄຌໃາປຄ(F)ຽຎັຌໃາຖ຺ຍ
5.1.1 ຄາຌຂບຄປຄີໃ ຉັໄຄຓຸຓກ ັຍຌທກາຌຽໃບຌີໃ
ກາຌາຌທຌນາຄາຌຈງເຆໄຘູຈ W=F.s ຌ ັໄຌຉໄບຄຖະທັຄທໃາ
ຈຂບຄປຄ(F)ກ ັຍກາຌກະ ັຈ(s)ຉໄບຄດູໃເຌຌທຂະໜາຌກ ັຌໃຄເຆໄາຌທຌນາຄາຌ(W)ແຈໄ,
ນາກປຄ(F),ຓີຈຉັໄຄຘາກກ ັຍກາຌກະ ັຈ(s) ໃາຂບຄປຄ(W) ະຓີໃາຽຎັຌຘູຌ(0), ນາກຈຂບຄປຄ(F)
ດູໃເຌຌທຄໃຼຄຉັໄຄຓຸຓກ ັຍກາຌກະ ັຈ(s) ເນໄຽປັຈກາຌຉກປຄຖໄທເຆໄປຄີໃ ດູໃເຌຌທຂະໜາຌກ ັຍກາຌກະ ັຈ
(s) ຽຎັຌຉ຺ທາຌທຌນາຄາຌ(W).