work done in increasing the size of soap film from 10cm x6cm to 10cmx 11cm is 3x10^-4 J
the surface tension of the film is
ans:3x10^-2 N/m
Work done in stretching the film is,
W = S × ΔA
where W is work done
S is the surface tension
ΔA is the change in area
given,
W = 3× 10-4 J
ΔA = 2 (10×11- 10×6 )
= 100 cm2 =10-2 m2
So,
S = W/ Δ A
= 3 ×10-4/10-2
= 3 × 10-2 N/m
W = S × ΔA
where W is work done
S is the surface tension
ΔA is the change in area
given,
W = 3× 10-4 J
ΔA = 2 (10×11- 10×6 )
= 100 cm2 =10-2 m2
So,
S = W/ Δ A
= 3 ×10-4/10-2
= 3 × 10-2 N/m