The surface tension of water is 75 dyne / cm. Find the minimum vertical force required to pull a thin wire ring up (refer figure) if it is initially resting on a horizontal water surface. The circumference of the ring is 20 cm and its. weight is 0.1 N :

Question

The surface tension of water is 75 dyne / cm. Find the minimum vertical force required to pull a thin wire ring up (refer figure) if it is initially resting on a horizontal water surface. The circumference of the ring is 20 cm and its. weight is 0.1 N : (A) 0.125 N (B) 0.225 N (C) 0.115 N (D) 0.130 N

Tardigrade Admin · Accepted Answer

F text req = mg +2[ T (2 π R )][ T =75 × 10-3 N / m ] =0.1+2[75 × 10-3(0.2)]=0.130 N

Q. The surface tension of water is $75 d y n e / c m$ . Find the minimum vertical force required to pull a thin wire ring up (refer figure) if it is initially resting on a horizontal water surface. The circumference of the ring is $20 c m$ and its. weight is $0.1 N$ :

$0.125 N$

$0.225 N$

$0.115 N$

$0.130 N$

$F_{req} = m g + 2 [T (2 π R)] [T = 75 \times 1 0^{- 3} N / m]$
$= 0.1 + 2 [75 \times 1 0^{- 3} (0.2)] = 0.130 N$

Q. The surface tension of water is 75dyne/cm. Find the minimum vertical force required to pull a thin wire ring up (refer figure) if it is initially resting on a horizontal water surface. The circumference of the ring is 20cm and its. weight is 0.1N :

0.125N

0.225N

0.115N

0.130N