The body stopped in 10 seconds at an initial speed of 60 km / h. Find the coefficient of friction

The body stopped in 10 seconds at an initial speed of 60 km / h. Find the coefficient of friction of the surface if the body mass is 1 kg.

Given:

m = 1 kilogram – body weight;

V0 = 60 km / h = 16.7 m / s – the initial speed of the body;

t = 10 seconds – the time during which the body completely stopped;

g = 10 m / s ^ 2 – acceleration of gravity.

It is required to determine the surface friction coefficient k.

Let’s find the acceleration of the body:

a = V0 / t = 16.7 / 10 = 1.67 m / s ^ 2.

Then, according to Newton’s second law:

F friction = m * a;

k * N = m * a;

k * m * g = m * a;

k * g = a;

k = a / g = 1.67 / 10 = 0.167 = 0.2.

Answer: the coefficient of friction of the surface is 0.2.