Answer:
Part a)
Part b)
t = 12 s
Explanation:
Part a)
Tension in the rope at a distance x from the lower end is given as
so the speed of the wave at that position is given as
here we know that
now we have
Part b)
time taken by the wave to reach the top is given as
Answer:
d = 4 d₀o
Explanation:
We can solve this exercise using the relationship between work and the variation of kinetic energy
W = ΔK
In that case as the car stops v_f = 0
the work is
W = -fr d
we substitute
- fr d₀ = 0 - ½ m v₀²
d₀ = ½ m v₀² / fr
now they indicate that the vehicle is coming at twice the speed
v = 2 v₀
using the same expressions we find
d = ½ m (2v₀)² / fr
d = 4 (½ m v₀² / fr)
d = 4 d₀o
Answer:
D. creates radioactive waste.
Explanation:
Nuclear energy can create nuclear radioactive waste
The correct answer is:
<span>C) The actual frequency of the siren does not change despite appearances.
In fact, Bob will observe an increase in the apparent frequency as the emergency vehicle approaches him, while Jill will observe a decrease in the apparent frequency as the emergency vehicle moves away from him, because of the Doppler effect (the relative velocity between the observer and the source of the sound is changing), but this effect involves the apparent frequency, while the real frequency of the siren will remain the same.</span>
