V o - initial velocity
v = velocity at the maximum height,
v² = v o² - 2 g h
v = 0
0 = v o² - 2 g h
v o² = 2 g h = 2 · 9.80 · 0.460
v o² = 9.052
v o = √9.052 = 3.004197 m/s ≈ 3 m/s
Answer:
The wavelength of wave is 7.5 meter.
Given:
Speed of wave = 1500 
Frequency of wave = 200 Hz
To find:
Wavelength of wave = ?
Formula used:

Where
= wavelength of the wave
v = speed of wave
n = frequency of wave
Solution:
Wavelength of wave is given by,

Where
= wavelength of the wave
v = speed of wave
n = frequency of wave

= 7.5 m
The wavelength of wave is 7.5 meter.
R=U^2/P=120*120/40=360 ohm
P2=U2^2/R=132*132/360=48.4 w
power increase ratio (48.4-40)/40=21%
Rt= ΣR = 40Ω
Vt= 80V
It= 80V/40Ω= 2A
V1= 15Ω*2A= 30V
V2= 20Ω*2A= 40V
V3= 5Ω*2A= 10V