Answer:
True the plastic will float because of the principle of flotation or buoyancy
Explanation:
Buoyancy explains it all!!
Buoyancy is the upward force/upthrust experienced by a body immersed totally or partially in a liquid.
According to the principle of flotation:
<em>"when a body is totally or partially immersed in liquid it experiences an upthrust which is equal to the volume of fluid displaced"</em>
The plastic will float due to the fact the average density of the total volume of the plastic and the air inside it is less than the same volume of water it is floating in
The person's horizontal position is given by

and the time it takes for him to travel 56.6 m is

so your first computed time is the correct one.
The question requires a bit of careful reading, and I think there may be a mistake in the problem. The person's vertical velocity
at time
is

which tells us that he would reach the ground at about
. In this time, he would have traveled

But we're told that he is caught by a net at 56.6 m, which would mean that the net cannot have been placed at the same height from which he was launched. However, it's possible that the moment at which he was launched doesn't refer to the moment the cannon went off, but rather the moment at which the person left the muzzle of the cannon a fraction of a second after the cannon was set off. After this time, the person's initial vertical velocity
would have been a bit smaller than
.
Answer:
i speak english not spanigh sorry :(
Explanation:
Answer:
C
Explanation:
Answer A: A surface wave is a wave that travels along the surface of a medium.
Answer B, C: Electromagnetic waves are waves that have no medium to travel whereas mechanical waves need a medium for its transmission.
Answer D: The sentence in the answer D does not fit to the blank in the definition ( of the question )
......
Hope this answer can help you.