Answer:
3 Hz
Explanation:
A beat is the pattern of interference among two waves with frequencies which are different.
The difference of the frequencies of the waves gives us the beat frequency.
Here, one frequency is
, the other frequency is 
So, the beat frequency

The beat frequency that is produced is 3 Hz
<u>Answer:</u> 3
H = 45 m ,
time required for the stone
S = u.t+(1/2) g.t²
45 = (1/2) 9.81. t² since u( initial velocity) = 0 ; S =H.
t² = 9.17 s
<em> t = 3.02 s </em>
therefore answer is 3 m/s
<em> if you satisfy with explanation, please give brainiest ; </em>
Density =mass /volume
mass=density x volume
mass= 3.1g/mL x 25mL
mass=77.5g