Answer:
in region AB the body was not moving
in region BC the body was moving forward with a increasing velocity therefore accelerating constantly
in region CD the body was moving with a constant velocity hence zero acceleration
in region DE the body was moving backwards decelerating
Answer:
Part a)
![a = \frac{x}{L} g](https://tex.z-dn.net/?f=a%20%3D%20%5Cfrac%7Bx%7D%7BL%7D%20g)
Part b)
![T = \rho x g(1 - \frac{x}{L})](https://tex.z-dn.net/?f=T%20%3D%20%5Crho%20x%20g%281%20-%20%5Cfrac%7Bx%7D%7BL%7D%29)
Part c)
![v = \sqrt{gL}](https://tex.z-dn.net/?f=v%20%3D%20%5Csqrt%7BgL%7D)
Explanation:
Part a)
Net pulling force on the chain is due to weight of the part of the chain which is over hanging
So we know that mass of overhanging part of chain is given as
![m = \rho x](https://tex.z-dn.net/?f=m%20%3D%20%5Crho%20x)
now net pulling force on the chain is given as
![F = \rho x g](https://tex.z-dn.net/?f=F%20%3D%20%5Crho%20x%20g)
now acceleration is given as
![F = Ma](https://tex.z-dn.net/?f=F%20%3D%20Ma)
![\rho x g = \rho L a](https://tex.z-dn.net/?f=%5Crho%20x%20g%20%3D%20%5Crho%20L%20a)
![a = \frac{x}{L} g](https://tex.z-dn.net/?f=a%20%3D%20%5Cfrac%7Bx%7D%7BL%7D%20g)
Part b)
Tension force in the part of the chain is given as
![mg - T = ma](https://tex.z-dn.net/?f=mg%20-%20T%20%3D%20ma)
![\rho x g - T = \rho x a](https://tex.z-dn.net/?f=%5Crho%20x%20g%20-%20T%20%3D%20%5Crho%20x%20a)
![\rho x(g - a) = T](https://tex.z-dn.net/?f=%5Crho%20x%28g%20-%20a%29%20%3D%20T)
![\rho x (g - \frac{x}{L} g) = T](https://tex.z-dn.net/?f=%5Crho%20x%20%28g%20-%20%5Cfrac%7Bx%7D%7BL%7D%20g%29%20%3D%20T)
![T = \rho x g(1 - \frac{x}{L})](https://tex.z-dn.net/?f=T%20%3D%20%5Crho%20x%20g%281%20-%20%5Cfrac%7Bx%7D%7BL%7D%29)
Part c)
velocity of the last link of the chain is given as
![a = \frac{x}{L} g](https://tex.z-dn.net/?f=a%20%3D%20%5Cfrac%7Bx%7D%7BL%7D%20g)
![v\frac{dv}{dx} = \frac{x}{L} g](https://tex.z-dn.net/?f=v%5Cfrac%7Bdv%7D%7Bdx%7D%20%3D%20%5Cfrac%7Bx%7D%7BL%7D%20g)
now integrate both sides
![\int v dv = \frac{g}{L} \int x dx](https://tex.z-dn.net/?f=%5Cint%20v%20dv%20%3D%20%5Cfrac%7Bg%7D%7BL%7D%20%5Cint%20x%20dx)
![\frac{v^2}{2} = \frac{gL}{2}](https://tex.z-dn.net/?f=%5Cfrac%7Bv%5E2%7D%7B2%7D%20%3D%20%5Cfrac%7BgL%7D%7B2%7D)
![v = \sqrt{gL}](https://tex.z-dn.net/?f=v%20%3D%20%5Csqrt%7BgL%7D)
The threshhold for gamma rays is between 1 * 10^17 Hz and 9*10^17 Hz
Since this question goes much beyond that the answer is you much be working with a gamma ray. It is "Best" classified this way because nothing else will fit. The others are all much lower.
Construct an hypothesis <em /><em>(Because </em>the magnet wasn't attracted to the door, the door must be non-magnetic.) He has already made an observation (the magnent didn't stick), and already asked a question (<em>Why </em>didn't the magnent stick). However, he has not explained the results (there is no experiment yet).