Answer:
835.29 Hz
Explanation:
When moving towards the source of sound, frequency will be given by
f*=f(vd+v)/v
Where f is the freqiency of the source, vd is the driving speed, v is the speed of sound in air, f* is the inkown frequency when moving forward.
Substituting 800 Hz for f, 340 m/s for v and 15 m/s for vd then
f*=800(15+340)/340=835.29411764704 Hz
Rounded off, the frequency is approximately 835.29 Hz
Answer:
C) Plastic
Explanation:
Copper, silver, and gold all conduct electricity. Therefore, the material that would provide the most resistance for electricity would be plastic.
Six centimeters equal to about two inches
Answer:

Explanation:
Lets take
Resistance of bulb 1 =R₁
Resistance of bulb 2 =R₂
As we know that power P
P= ΔV²/R
Given that voltage difference is same for both bulbs
So
P₁R₁= ΔV² --------1
P₂R₂= ΔV² -----------2
When these resistance are connected in series then equivalent resistance R
R=R₁+ R₂
The new power P'
P'=ΔV²/R
P'R=ΔV² ------3
From equation 1 ,2 and 3
P'(R₁+ R₂) = ΔV²

