On an alien planet,an object moving at 4.0 m/s on the horizontal ground comes to rest after traveling a distance of 10 m.If the coefficient of kinetic friction between the object and the surface is 0.20,what is the value of g on that planet? A)4.0 m/s² B)6.0 m/s² C)8.0 m/s² D)10 m/s² E)12 m/s²

Question

Quizplus · Accepted Answer

Explanation:The work done by friction is:$$W_f=F_fd=\mu mgd$$The change in kinetic energy is:$$K_i-K_f=\frac{1}{2}mv_i^2-0=\frac{1}{2}mv_i^2$$By the work-energy theorem, we have:$$W_f=K_i-K_f$$$$\mu mgd=\frac{1}{2}mv_i^2$$$$g=\frac{v_i^2}{2\mu d}=\frac{(4.0	ext{ m/s})^2}{2(0.20)(10	ext{ m})}=\boxed{4.0	ext{ m/s}^2}$$

On an Alien Planet,an Object Moving at 4