A body of mass of \(4\;kg\) experiences two forces \(\vec{F_1}=5\hat i+8\hat j+7\hat k \) and \(\vec{F_2}=3\hat i-4\hat j-3\hat k\) then acceleration acting on the body \(R\)
A point source is emitting sound waves of intensity \( 16 \times 10^{-8} \, Wm^{-2} \) at the origin. The difference in intensity (magnitude only) at two points located at distances of 2 m and 4 m from the origin respectively will be _____ \( \times 10^{-8} \, Wm^{-2} \).
A bullet is fired into a fixed target looses one third of its velocity after travelling 4 cm. It penetrates further \( D \times 10^{-3} \) m before coming to rest. The value of \( D \) is :