Question

A body rolling on ice with vel. 8m/s comes to rest after traveling 4 m.Compute the co efficient of friction

Answer 1

Let u be the initial velocity and v be the final velocity
S be the displacement and a be the acceleration
K be the coefficient of friction
From kinematics,
v^2=u^2+2aS
0=8^2 +(2×a×4)
2×a×4=-8^2
8a=-64
a=-8 [-ve sign means retardation]
a=K.g=8(g is the acceleration due to gravity, value =10m/s)
Therefore a=K×10=8
K=0.8