Question

A wire forming a loop is dipped into soap solution and taken out,so that a film of soap solution is formed. a loop of 6.28cm long thread is gently put on the film and the film is wingspaned with a needle inside the loop. the thread loop takes the shape of a circle. Find the tension in the thread. Surface tension of soap solution=0.30N/m.

Answer 1

ST = F/L , where F is the tension in the thread or the force exerted across the spanned length which is 0.628 m as provided in the question. Thus the value of F according to the above relation becomes 0.4777 Newton.