GỢI Ý W= WĐ+WT => 1/2KA2=3/4*1/2KA2+1/2KX2=> X =A/2

câu 26: - DE THI THU DH 2012 DAP AN
DE THI THU DH 2012 DAP AN

Câu 26:

220 2

V. Câu 27: 3 cm.Gợi ý W= W

đ

+W

t

=> 1/2kA

2

=3/4*1/2kA

2

+1/2kx

2

=> x =A/2