Answer:
If the strings have same thickness but different lengths then these parameters wave frequency, speed, wavelength will be different in the two strings. so the option d) None of the above is correct.
Explanation:
Output Force, hope this helps.
Answer:
(a) Potential energy of the child is converted into the kinetic energy at the bottom off the slide and a part of which is lost into friction generating heat between the contact surfaces.
(b) 
Explanation:
Given:
- mass of the child,

- height of the slide,

- initial velocity of the child at the slide,

- final velocity of the child at the bottom of slide,

(a)
∴The initial potential energy of the child is converted into the kinetic energy at the bottom off the slide and a part of which is lost into friction generating heat between the contact surfaces.
Initial potential energy:



Kinetic energy at the bottom of the slide:



(b)
Now, the difference in the potential and kinetic energy is the total change in the thermal energy of the slide and the seat of her pants.
This can be given as:


