Answer: 45 joules of energy
Explanation:
Answer:
Explanation:
Given
inclination ![\theta =30^{\circ}](https://tex.z-dn.net/?f=%5Ctheta%20%3D30%5E%7B%5Ccirc%7D)
initial speed ![u=20\ m/s](https://tex.z-dn.net/?f=u%3D20%5C%20m%2Fs)
Point of release is 45 m above the ground
Considering stone to be a projectile, so time taken by projectile for its zero vertical displacement is
![t_1=\frac{2u\sin \theta }{g}](https://tex.z-dn.net/?f=t_1%3D%5Cfrac%7B2u%5Csin%20%5Ctheta%20%7D%7Bg%7D)
![t_1=\frac{2\times 20\times \sin 30}{10}](https://tex.z-dn.net/?f=t_1%3D%5Cfrac%7B2%5Ctimes%2020%5Ctimes%20%5Csin%2030%7D%7B10%7D)
![t_1=2\ s](https://tex.z-dn.net/?f=t_1%3D2%5C%20s)
Now after completing zero vertical displacement , stone needs to travel another 45 m in downward direction with initial speed u=20\sin 30
![h=u_yt+\frac{1}{2}a_yt^2](https://tex.z-dn.net/?f=h%3Du_yt%2B%5Cfrac%7B1%7D%7B2%7Da_yt%5E2)
where, ![h=height](https://tex.z-dn.net/?f=h%3Dheight)
![u_y=vertical velocity](https://tex.z-dn.net/?f=u_y%3Dvertical%20velocity)
![a_y=vertical acceleration](https://tex.z-dn.net/?f=a_y%3Dvertical%20acceleration)
![t_0=time](https://tex.z-dn.net/?f=t_0%3Dtime)
![45=20\sin 30+\frac{1}{2}(9.8)(t_0)^2](https://tex.z-dn.net/?f=45%3D20%5Csin%2030%2B%5Cfrac%7B1%7D%7B2%7D%289.8%29%28t_0%29%5E2)
![t_0^2=\frac{70}{9.8}](https://tex.z-dn.net/?f=t_0%5E2%3D%5Cfrac%7B70%7D%7B9.8%7D)
![t_0=2.64\ s](https://tex.z-dn.net/?f=t_0%3D2.64%5C%20s)
thus total time time required is ![t=t_0+t_1=2.64+2=4.64\ s](https://tex.z-dn.net/?f=t%3Dt_0%2Bt_1%3D2.64%2B2%3D4.64%5C%20s)
vertical velocity just before hitting
![v_y=\sqrt{u_y^2+2\times a_y\times s}](https://tex.z-dn.net/?f=v_y%3D%5Csqrt%7Bu_y%5E2%2B2%5Ctimes%20a_y%5Ctimes%20s%7D)
![v_y=\sqrt{10^2+2\times 10\times 45}](https://tex.z-dn.net/?f=v_y%3D%5Csqrt%7B10%5E2%2B2%5Ctimes%2010%5Ctimes%2045%7D)
![v_y=\sqrt{1000}=31.622\ m/s](https://tex.z-dn.net/?f=v_y%3D%5Csqrt%7B1000%7D%3D31.622%5C%20m%2Fs)
Horizontal velocity ![v_x=u\cos 30=17.32\ m/s](https://tex.z-dn.net/?f=v_x%3Du%5Ccos%2030%3D17.32%5C%20m%2Fs)
Net velocity Just before hitting ![=\sqrt{v_x^2+v_y^2}](https://tex.z-dn.net/?f=%3D%5Csqrt%7Bv_x%5E2%2Bv_y%5E2%7D)
![=\sqrt{(17.32)^2+(31.62)^2}](https://tex.z-dn.net/?f=%3D%5Csqrt%7B%2817.32%29%5E2%2B%2831.62%29%5E2%7D)
![=\sqrt{1299.82}=36.05\ m/s](https://tex.z-dn.net/?f=%3D%5Csqrt%7B1299.82%7D%3D36.05%5C%20m%2Fs)
Answer:
Explanation:
But the reality is that: Multiple magnetic fields would fight each other. This could weaken Earth's protective magnetic field by up to 90% during a polar flip. Earth's magnetic field is what shields us from harmful space radiation which can damage cells, cause cancer, and fry electronic circuits and electrical grids.
How do magnetic poles interact? Magnetic poles that are alike repel each other, and magnetic poles that are unlike attract each other. The area of magnetic force around a magnet. The magnetic field lines spread out from the north pole, curve around, and return to the south pole.
When two magnets are brought together, the opposite poles will attract one another, but the like poles will repel one another. This is similar to electric charges. The earth is like a giant magnet, but unlike two free hanging magnets, the north pole of a magnet is attracted to the north pole of the earth.
Magnetic forces are non contact forces; they pull or push on objects without touching them. Magnets are only attracted to a few 'magnetic' metals and not all matter. Magnets are attracted to and repel other magnets.
(hope this helps can i plz have brainlist :D hehe)