Answer:
Time=7.84hrs
Explanation:
This is an inverse proportionality questions
Mathematically time t varies as 1/distance d
Hence T= dk/r
But speed r = distance/t
d= r*t= 9*20=180km/hr
We're k= constant of proportionality
At t=9hrs d=180km/hr
Hence k=r*t/d=20*9/1620=0.111
Finding t at at 1620km for 23km/hr
t=1620*0.111/23=7.84hrs
Answer:
The wave speed is 2.8 m.
Explanation:
Wavelength = 1.4 m
frequency, f = 2 Hz
the wave speed is given by
wave speed = wavelength x frequency
wave speed = 1.4 x 2 = 2.8 m
option (D) is correct.
It is an Insulator I’m pretty sure