Answer:9.75 m/s
Explanation:
Given
Length of ladder ![(L)=5 m](https://tex.z-dn.net/?f=%28L%29%3D5%20m)
Foot the ladder is moving away with speed of ![\frac{\mathrm{d} x}{\mathrm{d} t}=13 m/s](https://tex.z-dn.net/?f=%5Cfrac%7B%5Cmathrm%7Bd%7D%20x%7D%7B%5Cmathrm%7Bd%7D%20t%7D%3D13%20m%2Fs)
From diagram
------1
at ![x=3](https://tex.z-dn.net/?f=x%3D3%20)
![y^2=25-9=16](https://tex.z-dn.net/?f=y%5E2%3D25-9%3D16)
![y=4 m](https://tex.z-dn.net/?f=y%3D4%20m)
Now differentiating equation 1 w.r.t time
![2x\frac{\mathrm{d} x}{\mathrm{d} t}+2y\frac{\mathrm{d} y}{\mathrm{d} t}=0](https://tex.z-dn.net/?f=2x%5Cfrac%7B%5Cmathrm%7Bd%7D%20x%7D%7B%5Cmathrm%7Bd%7D%20t%7D%2B2y%5Cfrac%7B%5Cmathrm%7Bd%7D%20y%7D%7B%5Cmathrm%7Bd%7D%20t%7D%3D0)
![x\frac{\mathrm{d} x}{\mathrm{d} t}=-y\frac{\mathrm{d} y}{\mathrm{d} t}](https://tex.z-dn.net/?f=x%5Cfrac%7B%5Cmathrm%7Bd%7D%20x%7D%7B%5Cmathrm%7Bd%7D%20t%7D%3D-y%5Cfrac%7B%5Cmathrm%7Bd%7D%20y%7D%7B%5Cmathrm%7Bd%7D%20t%7D)
![3\times 13=-4\times \frac{\mathrm{d} y}{\mathrm{d} t}](https://tex.z-dn.net/?f=3%5Ctimes%2013%3D-4%5Ctimes%20%5Cfrac%7B%5Cmathrm%7Bd%7D%20y%7D%7B%5Cmathrm%7Bd%7D%20t%7D)
![\frac{\mathrm{d} y}{\mathrm{d} t}=-\frac{3\times 13}{4}=-9.75 m/s](https://tex.z-dn.net/?f=%5Cfrac%7B%5Cmathrm%7Bd%7D%20y%7D%7B%5Cmathrm%7Bd%7D%20t%7D%3D-%5Cfrac%7B3%5Ctimes%2013%7D%7B4%7D%3D-9.75%20m%2Fs)
negative indicates distance is decreasing with time
Explanation:
Variety in to an exercise program allows the body to adapt to many demands, from high intensity exercise to slow, steady state exercise. Variety is important in a fitness program because it allows for your body to be challenged on a consistent basis and to overcome a plateau.
Sure what do u need help with
Answer:
the water will boil and change into a gas
Explanation:
This is because it is exothermic and releases the energy into the surroundings and the fact that water boils at 100 degrees Celsius
Explanation:
Formula which holds true for a leans with radii
and
and index refraction n is given as follows.
Since, the lens is immersed in liquid with index of refraction
. Therefore, focal length obeys the following.
and,
or,
= 32.4 cm
Using thin lens equation, we will find the focal length as follows.
![\frac{1}{f} = \frac{1}{s_{o}} + \frac{1}{s_{i}}](https://tex.z-dn.net/?f=%5Cfrac%7B1%7D%7Bf%7D%20%3D%20%5Cfrac%7B1%7D%7Bs_%7Bo%7D%7D%20%2B%20%5Cfrac%7B1%7D%7Bs_%7Bi%7D%7D)
Hence, image distance can be calculated as follows.
![s_{i} = \frac{fs_{o}}{s_{o} - f}](https://tex.z-dn.net/?f=s_%7Bi%7D%20%3D%20%5Cfrac%7Bfs_%7Bo%7D%7D%7Bs_%7Bo%7D%20-%20f%7D)
![s_{i} = \frac{32.4 \times 100}{100 - 32.4}](https://tex.z-dn.net/?f=s_%7Bi%7D%20%3D%20%5Cfrac%7B32.4%20%5Ctimes%20100%7D%7B100%20-%2032.4%7D)
= 47.9 cm
Therefore, we can conclude that the focal length of the lens in water is 47.9 cm.