The most effective way to prevent beach erosion is to replant mangrove trees, seaweeds and seagrass. The strategic planting of vegetation can be used to help control erosion. The roots of these plants help to anchor the sand and ensure that it is not carried off in erosion. This is why many areas plant seagrass and build marshes along coasts to prevent erosion.
Answer: 0 m
Explanation:
Let's begin by stating clear that movement is the change of position of a body at a certain time. So, during this movement, the body will have a trajectory and a displacement, being both different:
The trajectory is the <u>path followed by the body</u> (is a scalar quantity).
The displacement is <u>the distance in a straight line between the initial and final position</u> (is a vector quantity).
According to this, in the description Matthew's home is placed at 0 on a number line, then he moves 10 m to the park (this is the distance between the park and Mattew's home), then 15 m to the movie theatre until he finally comes back to his home (position 0). So, in this case we are talking about the <u>path followed by Matthew</u>, hence <u>his trajectory</u>.
However, if we talk about Matthew's displacement, we have to draw a straight line between Matthew's initial position (point 0) to his final position (also point 0).
Now, being this an unidimensional problem, the displacement vector for Matthew is 0 meters.
Answer: Your question is missing below is the question
Question : What is the no-friction needed speed (in m/s ) for these turns?
answer:
20.1 m/s
Explanation:
2.5 mile track
number of turns = 4
length of each turn = 0.25 mile
banked at 9 12'
<u>Determine the no-friction needed speed </u>
First step : calculate the value of R
2πR / 4 = πR / 2
note : πR / 2 = 0.25 mile
∴ R = ( 0.25 * 2 ) / π
= 0.159 mile ≈ 256 m
Finally no-friction needed speed
tan θ = v^2 / gR
∴ v^2 = gR * tan θ
v = √9.81 * 256 * tan(9.2°) = 20.1 m/s
