Consider the apparatus shown in figure (a) below, where the hanging object has m
ID: 2245766 • Letter: C
Question
Consider the apparatus shown in figure (a) below, where the hanging object has mass M and the string is vibrating in its second harmonic. The vibrating blade at the left maintains a constant frequency. The wind begins to blow to the right, applying a constant horizontal force on the hanging object. What is the magnitude of the force the wind must apply to the hanging object so that the string vibrates in its first harmonic as shown in figure (b) below? (Use any variable or symbol stated above along with the following as necessary: g.) F =Explanation / Answer
Lambda1=L
Lambda2=L/2
frequency is same so
lambda1/lambda2=v1/v2
==>2=v1/v2
==>sqrt(T1)/sqrt(T2)=2
==> T1/T2=4
==> sqrt((mg)^2 +F^2)/mg=4
==>F=sqrt(15)* mg=3.87 mg