Answer:4
Explanation:
Given
Frequency of beats is 3 beats per second
Frequency of first tuning fork is 
Beat frequency is difference in the frequency of tuning forks i.e.
either
or 
so 
or

so there is not enough information given to decide.
Answer:
7.50 cm
Explanation:
The formula
1/v + 1/u = 1/f
Is used.
where.
u is the object distance.
v is the image distance.
f is the focal length of the lens.
1/v + 1/15 = 1/5
1/v = 1/5 - 1/15
1/v = (3-1)/15
1/v = 2/15
2v = 15
V = 15/2
V = 7.5 cm
For focal length, f in lens is always taken as negative for concave and positive for convex. ... And for image distance, V in lens it is taken as positive in Convex lens since image is formed on +X side. It is taken as negative in Concave lens since image is formed in -X side of the Cartesian.
Nowadays, most of the walkie talkies ... and all R/C models ... operate in the "Family Radio Service" (FRS) band. That's 46-49 MHz. The wavelength is 6.12-6.52 meters.
Answer:
1.5 hours
Explanation:
Using the equation t=d/v to solve for time:
t=75 miles ÷ 50 miles per hour = 1.5 hours