Question

A 15-kg sled is being pulled along the horizontal snow-covered ground by a horizontal force of 23 n. starting from rest, the sled attains a speed of 1.8 m/s in 8.5 m. find the coefficient of kinetic friction between the runners of the sled and the snow.

Answer 1

We know the relationship between distance traveled and velocity obtained under acceleration a:

`a=(v^2)/(2S)=(1.8^2)/(2\cdot8.5)=0.19(m)/(s^2)`
We know from second Newtons law that net force acting on the object is proportional to its mass and acceleration:

`F_n=ma`
The net force acting on the sledge is:

`F_p-F_f=ma\\ F_f=F_p-ma\\ \mu mg=F_p-ma\\ \mu=(F_p-ma)/(mg)\\ \mu=(23-15\cdot0.19)/(15\cdot 9.81)=0.14`