3 is false 2 is true and the rest true
If the force were constant or increasing, we could guess that the speed of the sardines is increasing. Since the force is decreasing but staying in contact with the can, we know that the can is slowing down, so there must be friction involved.
Work is the integral of (force x distance) over the distance, which is just the area under the distance/force graph.
The integral of exp(-8x) dx that we need is (-1/8)exp(-8x) evaluated from 0.47 to 1.20 .
I get 0.00291 of a Joule ... seems like a very suspicious solution, but for an exponential integral at a cost of 5 measly points, what can you expect.
On the other hand, it's not really too unreasonable. The force is only 0.023 Newton at the beginning, and 0.000067 newton at the end, and the distance is only about 0.7 meter, so there certainly isn't a lot of work going on.
The main question we're left with after all of this is: Why sardines ? ?
Answer:
The slope of the graph is what you need. That tells you the speed not the velocity. In order to find the velocity you would also need to know the direction of the motion.
Answer:
= 1.7 cm
Explanation:
The magnification of the compound microscope is given by the product of the magnification of each lens
M = M₀ 
M = - L/f₀ 25/
Where f₀ and are the focal lengths of the lens and eyepiece, respectively, all values in centimeters
In this exercise they give us the magnification (M = 400X), the focal length of the lens (f₀ = 0.6 cm), the distance of the tube (L = 16 cm), let's look for the focal length of the eyepiece ()
= - L / f₀ 25 / M
Let's calculate
= - 16 / 0.6 25 / (-400)
= 1.67 cm
The minus sign in the magnification is because the image is inverted.
= 1.7 cm
