Answer:
37.42 m/s
Explanation:
We know that apparent frequency, 
is given by
where f is the given frequency in this case 392, V is the speed of sound in air which is given as 343 and 
is the speed of car which is unknown, \bar f is given as 440 Hz
Parfocal is the term used to describe a microscope that maintains focus when the objective lenses are replaced.
<h3>
What is the name of the objective lens ?</h3>
For observing minute features within a specimen sample, a high-powered objective lens, often known as a "high dry" lens, is perfect. You can see a very detailed image of the specimen on your slide thanks to the 400x total magnification that a high-power objective lens and a 10x eyepiece provide.
The four objective lenses on your microscope are for scanning (4x), low (10x), high (40x), and oil immersion (100x).
The first-stage lens used to create a picture from electrons leaving the specimen is referred to as the "objective lens." The objective lens is the most crucial component of the imaging system since the quality of the images is determined by how well it performs (resolution, contrast, etc.,).
To learn more than objective lens , visit
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Answer:
C
Explanation:
For the explained scenario in the free body force diagram definitely the two forces 1200 N and 800 N should present as they are the acting forces
So A & D rules out.
Then you must think of B & C.
You also know that the weight of the load is always acting downwards as that force is generated by gravitational field of Earth. So 800 N should be downwards not upwards. That rules out B.
So answer is C
(Free body diagram is shown in the graph)
