A) 0.5
B) 0.3
C) 0.2
D) 0.1
Correct Answer: A
Solution :
Key Idea: Final velocity is zero. From equation of motion \[{{v}^{2}}={{u}^{2}}-2as\] where v is final velocity, u the initial velocity, a the acceleration and 5 the displacement. Given, \[v=0,\text{ }u=20\text{ }m/s,\text{ }s=40\text{ }m\] \[\therefore \] \[0={{(20)}^{2}}-2\times 40\times a\] \[\Rightarrow \] \[a=5\text{ }m/{{s}^{2}}\] Kinetic (or dynamic) friction occurs when two objects are moving relative to each other and rub together. It is -given by \[{{\mu }_{x}}=\frac{a}{g}=\frac{5}{10}=0.5\]You need to login to perform this action.
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