Answer:
102 kg.m/s
Explanation:
m = Mass of hammer = 12 kg
v = Final velocity = 8.5 m/s
u = Initial velocity = 0
t = Time taken = 8 ms
Force acting over a given amount of time or change in momentum is known as impulse.
Impulse
![J=Ft\\\Rightarrow J=p_2-p_1\\\Rightarrow J=m(v-u)\\\Rightarrow J=12(8.5-0)\\\Rightarrow J=102\kg.m/s](https://tex.z-dn.net/?f=J%3DFt%5C%5C%5CRightarrow%20J%3Dp_2-p_1%5C%5C%5CRightarrow%20J%3Dm%28v-u%29%5C%5C%5CRightarrow%20J%3D12%288.5-0%29%5C%5C%5CRightarrow%20J%3D102%5Ckg.m%2Fs)
Impulse given to the nail is 102 kg.m/s
Just took the test and the answer is <span>C. 1,314,718.
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Answer:
26036485.6433 W/m²
Explanation:
E= Energy = 470 J
t = Time = 4 seconds
d = Diameter = 2.6 mm
Power is given by
![P=\dfrac{E}{t}](https://tex.z-dn.net/?f=P%3D%5Cdfrac%7BE%7D%7Bt%7D)
Intensity is given by
![I=\dfrac{P}{\pi r^2}\\\Rightarrow 0.85I=\dfrac{E}{t\dfrac{\pi}{4} d^2}\\\Rightarrow I=\dfrac{470}{0.85\times 4\times \dfrac{\pi}{4}\times (2.6\times 10^{-3})^2}\\\Rightarrow I=26036485.6433\ W/m^2](https://tex.z-dn.net/?f=I%3D%5Cdfrac%7BP%7D%7B%5Cpi%20r%5E2%7D%5C%5C%5CRightarrow%200.85I%3D%5Cdfrac%7BE%7D%7Bt%5Cdfrac%7B%5Cpi%7D%7B4%7D%20d%5E2%7D%5C%5C%5CRightarrow%20I%3D%5Cdfrac%7B470%7D%7B0.85%5Ctimes%204%5Ctimes%20%5Cdfrac%7B%5Cpi%7D%7B4%7D%5Ctimes%20%282.6%5Ctimes%2010%5E%7B-3%7D%29%5E2%7D%5C%5C%5CRightarrow%20I%3D26036485.6433%5C%20W%2Fm%5E2)
The intensity of the laser beam is 26036485.6433 W/m²
I am pretty sure the answer is an energy source