Explanation:
The speed of a wave is given by :
......(1)
(i) Here, the wavelength of a sound wave in air reduces by a factor of 3. Equation (1) becomes :

Wavelength and frequency are inversely proportional to each other. So, if wavelength of a sound wave in air reduces by a factor of 3, then the frequency will increases by a factor of 3.
(ii) It remains the same.
Answer:
34 m/s
Explanation:
m = Mass of glider with person = 680 kg
v = Velocity of glider with person = 34 m/s
= Mass of glider without person = 680-60 kg
= Gliders speed just after the skydiver lets go
= Mass of person = 60 kg
= Velcotiy of person = 34 m/s
As the linear momentum of the system is conserved

The gliders speed just after the skydiver lets go is 34 m/s
When you hit a ball it collides with the bat. When you catch a ball it collides with your hand.