Answer:
Explanation:
work done=force * displacement
=500 N * 40 m
=2000 joule
Answer:
The thrown rock will strike the ground earlier than the dropped rock.
Explanation:
<u>Known Data</u>
- , it is negative as is directed downward
<u>Time of the dropped Rock</u>
We can use , to find the total time of fall, so , then clearing for .
<u>Time of the Thrown Rock</u>
We can use , to find the total time of fall, so , then, , as it is a second-grade polynomial, we find that its positive root is
Finally, we can find how much earlier does the thrown rock strike the ground, so
The sonar pulse takes t=4.2 s to reach the ocean bottom and then to travel back tothe ship. If we call d the depth of the ocean bottom, this means that the sonar pulse covered a distance equal to 2d in a time of 4.2 s.
The speed of the sonar pulse is the speed of sound in water at 25C, so looking at the table is v=1493 m/s. Using the relationship
between space and time for a uniform motion, and keeping in mind that the total distance covered by the pulse is 2d, we can write:
which becomes
so, the ocean bottom is 3135 m deep.
Answer: They create antibodies.