Answer:
1.2 rad/s
Explanation:
m1 = 15 g, m2 = 9 g, ω1 = 0.75 rad/s
Let the new angular speed is ω2 and the radius of the table be r.
The angular momentum is conserved when no external torque is applied.
I1 ω1 = I2 ω2
(m1 + m2)x r^2 x 0.75 = m1 x r^2 x ω2
(15 + 9) x 0.75 = 15 x ω2
ω2 = 1.2 rad/s
The Doppler effect is the right concept to solve this problem. The Doppler effect is understood as the change in apparent frequency of a wave produced by the relative movement of the source with respect to its observer. Mathematically it can be described as,

Here,
= Frequency of the sound from the Whistle
f = Frequency of sound heard
v = Speed of the sound in the Air
Replacing we have that





Therefore the minimum speed to know if the whistle is working is 16.33m/s
Explanation:
<h2>Newton's first law of motion states that everybody continues in its state of rest or of uniform motion in a straight line unless an external force is applied on it. </h2>
Its is called intertidal zone
Explanation:
The earth rotation and the moon's pull of gravity causes the tides to rise and fall.High tides occur when the water advances to the furthers point of a shoreline where as low tides happen when the water recedes to the lowest point of the shoreline.Some kinds of animal and plants survive in the ecosystem present between the area of high tides and low tides refered to as the intertidal zone.This area is sometimes covered or uncovered by ocean waters.
Learn More
Intertidal zone:brainly.com/question/1346004
Keywords: area, shoreline, high tides, low tides.
#LearnwithBrainly