Question

1) A 500 kg sled is pulled along a horizontal surface at uniform speed by a rope that makes an angle of 30 degrees above the horizontal. Find mu if the tension in the rope is 200 N.

Answer 1

As the velocity is constant, the result of the forces in the sled is zero. If
`T_x` is the horizontal component of the traction and
`F_(at)` is the frictional force:


`F_R=0\iff T_x=F_(at)\iff T\cos30^o=\mu N\iff \\\\ T\cos30^o=\mu P\iff 200\cdot(\sqrt3)/(2)=\mu (500\cdot10)\iff 100\sqrt3=5000\mu\\\\\mu=(100\sqrt3)/(5000)\iff \mu=(\sqrt3)/(50)\Longrightarrow\boxed{\mu\approx0,035}`

Answer 2

Coefficient of friction ( mu) is 0.035