The work done to pull the object 7.0 m is the total area under the graph from 0.0 m to 7.0 m, determined as 245 J.
<h3>Work done by the applied force</h3>
The area under force versus displacement graph is work done.
The total work done by pulling the object 7 m, can be grouped into two areas;
- First area, A1 = area of triangle from 0 m to 2.0 m
- Second area, A2 = area of trapezium, from 2.0 m to 7.0 m
A1 = ¹/₂ bh
A1 = ¹/₂ x (2) x (20)
A1 = 20 J
A2 = ¹/₂(large base + small base) x height
A2 = ¹/₂[(7 - 2) + (7-3)] x 50
A2 = ¹/₂(5 + 4) x 50
A2 = 225 J
<h3>Total work done </h3>
W = A1 + A2
W = 20 J + 225 J
W = 245 J
Learn more about work done here: brainly.com/question/8119756
Answer:
The sound travels differently in different medium according the density of the medium.
Explanation:
The sound travels faster in dense medium and can be heard by the vibration of the bone present in the ear. The ear plugs reduce the sound intensity in both medium water and on land (air).
In air the sound is not heard properly due to the earplugs that stops the as the vibration are not able to produce as sound is not able to reach to middle ear, but Navy researchers have discovered that sound under water is heard by the bone present behind the ear, vibrations mastoid.
I believe it's the the third one. :)
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