<span>Pitch and frequency are more or less the same thing - high pitch = high frequency.
The freqency of vibration of a string f = 1/length (L) so as length decreases the frequency increases.</span>
The answer would be B: The ground exerts an equal force on the golf ball.
Explanation:
Given that,
Work done to stretch the spring, W = 130 J
Distance, x = 0.1 m
(a) We know that work done in stretching the spring is as follows :

(b) If additional distance is 0.1 m i.e. x = 0.1 + 0.1 = 0.2 m
So,

So, the new work is more than 130 J.