95. Let the original tension be τ

1

and the new tension be τ

2

. Then

λ

s2

λ

s1

=

v

s

/f

2

v

s

/f

1

=

f

1

f

2

=

v

2

/λ

1

v

2

/λ

2

=

v

1

v

2

=

τ

1

τ

2

=

1

2

.

Thus, τ

2

/τ

1

= 4. That is, the tension must be increased by a factor of 4.