Technically, they do have a skeleton. The hard shell it has is called an exoskeleton. It works just like our skeleton, in terms of muscles and support. And, it protects from harm, similar to the way our skin protects the inside of our body from dirt and such.
The answer is A) frequency
The amplitude of Wave 2 is greater than Wave 1's, as is the wavelength. You can see that Wave 2 has a higher period and greater peaks and troughs than Wave 1.
You can also see that Wave 2 has half the frequency, meaning Wave 1 completes 2 periods for every 1 period that Wave 2 completes.
I would say that it depends on the size of the animal and where it was hit. It is possible that a large animal could survive.
The answer is 3, 240J
KE=1/2 m v^2
KE= 1/2(45kg)(12m/s)^2
KE=1/2*45*144
KE= 3, 240 Joules