Answer:
Oracio is the most cost-effective choice because he would cost the least to complete the project. However, he would also take the longest amount of time. Camilla could complete the job the fastest, but she costs more than Oracio. SciTech will have to decide if it is more important to save money or complete the work quickly to meet the deadline.
Hope this helps :)
True because school doesn't dictate what job you want in the future
For a standing wave on a string, the wavelength is equal to twice the length of the string:

In our problem, L=50.0 cm=0.50 m, therefore the wavelength of the wave is

And the speed of the wave is given by the product between the frequency and the wavelength of the wave:
The mass of the object will remain the same rather it's on the moon or on the Earth and even in other places. But the weight will change on the moon, so its weight will be different from the one it had on Earth