Answer:
39267.96 Hz
Explanation:
Given:
Frequency emitted = 16246 Hz
Speed of source = 141 m/s
Speed of observer = 141 m/s
Let the velocity of sound is v = 340 m/s
Doppler effect is nothing but the change in the wavelength or frequency of a wave relative to the observer, who is also moving relative to the origin of the wave source.
Therefore, Doppler effect when the source and the observer moves towards each other,
Frequency heard = ( frequency emitted ) ( Velocity of sound + Speed of the observer ) / ( velocity of sound - speed of source )
16246 x ( 340 + 141 ) / ( 340 - 141 )
= 39267.96 Hz
Answer: D allowing businesses to release industrial wastes into rivers
Answer:
0.50m/s
Explanation:
Average velocity is the change in displacement of a body with respect to time.
Velocity = ∆S/∆t
∆S = 100m - 70m
∆S = 30m
∆t = 2min - 1 min
∆t = 1min = 60secs
Substitute the given parameters into the formula for velocity
Velocity = 30m/60s
Velocity = 1/2 m/s
Average Velocity = 0.5m/s
According to the conservation of mechanical energy, the kinetic energy just before the ball strikes the ground is equal to the potential energy just before it fell.
Therefore, we can say KE = PE
We know that PE = m·g·h
Which means KE = m·g·h
We can solve for h:
h = KE / m·g
= 20 / (0.15 · 9.8)
= 13.6m
The correct answer is: the ball has fallen from a height of 13.6m.
