Answer:
the correct answer is the 60

Well, there would have to major supports on every building that was tall even though we have very strong foundation the foundation doesn't do anything except no give us dirt as a floor.but a really strong structure to use is a triangle formation.
Hope this helped
The frequency of a wave is the number of complete oscillations passing a given point per second.
In this case, assuming the duck is stationary, we have 4 complete waves passing the duck in one second: therefore, the frequency of the wave is
Answer:

Explanation:
When a spring is compressed, the force exerted by the spring is given by:

where
k is the spring constant
x is the compression of the spring
In this problem we have:
k = 52 N/m is the spring constant
x = 43 cm = 0.43 m is the compression
Therefore, the force exerted by the spring on the dart is

Now we can apply Newton' second law of motion to calculate the acceleration of the dart:

where
F = 22.4 N is the force exerted on the dart by the spring
m = 75 g = 0.075 kg is the mass of the dart
a is its acceleration
Solving for a,
