Answer:
= 53.4 m/s
Explanation:
Velocity of a sound is given by the formula;
Velocity = Frequency × 2 (Length)
Frequency = 30 Hz
Length = 89 cm, equivalent to 0.89 M
Therefore;
Velocity = 30 × 2 ×0.89
= 53.4 m/s
Thus; the velocity or the speed of sound is 53.4 m/s
The Newton's law that explains why the hands get red when you press them hard against a wall is Newton's third law. When one body exerts a force on a second body, the second body simultaneously exerts a force equal in magnitude and opposite in direction on the first body.
V=IR
I=V/R
when voltage is divided by 2, I=V/2R
since resistance is also divided by 2, I=V/R
therefore, there is no effect on the current
Answer: Compressions and Rarefractions
Explanation: places where particles of a medium crowd close together are compressions and places where they spread farther apart are called rarefactions. The more energy the wave has the closer together the compressions can be and the farther apart the rarefactions will be.
Answer:
The resistance added to this coil is 0.04 ohm in parallel.
Explanation:
Given that,
Current I'= 0.5 A
Resistance R= 20 ohm
Deflection I= 1 mA
We need to calculate the resistance
Using ohm's law
Where,
V = voltage
I =current
R = resistance
V is constant so ,
Therefore,
I R=I'R'
Hence, The resistance added to this coil is 0.04 ohm in parallel.
