Answer:8.1 m
Explanation:
Given
ball is launched from height of 3 m
initial velocity ![u=10 m/s](https://tex.z-dn.net/?f=u%3D10%20m%2Fs)
considering the ball is thrown vertically upward
Using ![v^2-u^2=2 as](https://tex.z-dn.net/?f=v%5E2-u%5E2%3D2%20as)
where,
u=initial velocity
v=final Velocity
a=acceleration
s=distance
At maximum height final velocity will be zero
![v^2-u^2=2 gs](https://tex.z-dn.net/?f=v%5E2-u%5E2%3D2%20gs)
![0-10^2=2(-9.8)\cdot h](https://tex.z-dn.net/?f=0-10%5E2%3D2%28-9.8%29%5Ccdot%20h)
![h=5.10 m](https://tex.z-dn.net/?f=h%3D5.10%20m)
Therefore maximum height w.r.t ground is ![3+5.10=8.10 m](https://tex.z-dn.net/?f=3%2B5.10%3D8.10%20m)
The statement which is true of a wave that’s propagating along the pavement and girders of a suspension bridge is A. The wave is mechanical, with particles vibrating in a direction that is parallel to that of the wave, forming compressions and rarefactions.
Answer:
Explanation:
Given
mass of spring ![m=100\ gm](https://tex.z-dn.net/?f=m%3D100%5C%20gm)
extension in spring ![x=5\ cm](https://tex.z-dn.net/?f=x%3D5%5C%20cm)
downward velocity ![v=70\ cm/s](https://tex.z-dn.net/?f=v%3D70%5C%20cm%2Fs)
Position in undamped free vibration is given by
![u(t)=A\cos \omega _0t+B\sin \omega _0t](https://tex.z-dn.net/?f=u%28t%29%3DA%5Ccos%20%5Comega%20_0t%2BB%5Csin%20%5Comega%20_0t)
where ![\omega _0^2=\frac{k}{m}](https://tex.z-dn.net/?f=%5Comega%20_0%5E2%3D%5Cfrac%7Bk%7D%7Bm%7D)
also ![\frac{k}{m}=\frac{g}{L}](https://tex.z-dn.net/?f=%5Cfrac%7Bk%7D%7Bm%7D%3D%5Cfrac%7Bg%7D%7BL%7D)
![\omega _0^2=\frac{k}{m}=\frac{9.8}{0.05}](https://tex.z-dn.net/?f=%5Comega%20_0%5E2%3D%5Cfrac%7Bk%7D%7Bm%7D%3D%5Cfrac%7B9.8%7D%7B0.05%7D)
![\omega _0=14](https://tex.z-dn.net/?f=%5Comega%20_0%3D14)
![u(t)=A\cos(14t)+B\sin(14t)](https://tex.z-dn.net/?f=u%28t%29%3DA%5Ccos%2814t%29%2BB%5Csin%2814t%29)
it is given
![u(0)=0](https://tex.z-dn.net/?f=u%280%29%3D0)
![u'(0)=70\ cm/s](https://tex.z-dn.net/?f=u%27%280%29%3D70%5C%20cm%2Fs)
substituting values we get
![A=0](https://tex.z-dn.net/?f=A%3D0)
![u(t)=B\sin (14t)](https://tex.z-dn.net/?f=u%28t%29%3DB%5Csin%20%2814t%29)
![u'(t)=14B\cos (14t)](https://tex.z-dn.net/?f=u%27%28t%29%3D14B%5Ccos%20%2814t%29)
![70=14B](https://tex.z-dn.net/?f=70%3D14B)
![B=\frac{10}{2}](https://tex.z-dn.net/?f=B%3D%5Cfrac%7B10%7D%7B2%7D)
![B=5](https://tex.z-dn.net/?f=B%3D5)
![u(t)=5\sin (14t)](https://tex.z-dn.net/?f=u%28t%29%3D5%5Csin%20%2814t%29)
Ultraviolet light. It can cause skin cancer and that is why we wear sunscreen. We also wear sunglasses because some research has shown that it can damage eyes. Although it can be dangerous, it can also kill certain bacterias.