Answer is OB
Answer is OB
Answer is OB
Answer:
0.002833 sec
Explanation:
Speed of light in vacuum is 
Given distance = 850 km = 850×1000=850000 m
We have to calculate the time that light take to travel the distance 850 km
Time 
So the time taken by light to travel 850 km is 0.002833 sec
Answer:We have , a relation in frequency f and wavelength λ of a wave having the velocity v as ,
v=fλ ,
given f=60Hz , λ=20m ,
therefore velocity of wave , v=60×20=1200m/s
Answer:

Explanation:
Radius of the pollen is given as

Volume of the pollen is given as



mass of the pollen is given as


so weight of the pollen is given as



Now electric force on the pollen is given



now ratio of electric force and weight is given as


Answer:
v = 72.54 m/s
Explanation:
We have,
Length of a guitar string is 0.62 m
Frequency of a guitar string is 234 Hz
For guitar string,

The velocity of the wave in the string is given by :

So, the velocity of the waves in the string is 72.54 m/s.