A) 12. 75
B) 16. 35
C) 18. 25
D) 20
Correct Answer: B
Solution :
Acceleration of block down the plane. \[a=\frac{\mu \,mg\,\cos \theta -mg\,\sin \,\theta }{m}\] \[=\mu g\cos \theta -g\sin \theta \] \[=0.2\times 10\times \cos {{30}^{o}}-10\times \sin {{30}^{o}}\] \[=2\times \frac{\sqrt{3}}{2}-10\times \frac{1}{2}\] \[=\sqrt{3}-5\] \[=1.73-5\] \[=-3.278\,m/{{s}^{2}}\] From equation of motion, \[v=u-at\] Velocity after 5 s \[v=0+0.327\times 5\] \[=16.35\,\,m/s\]You need to login to perform this action.
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