A body, of mass m, moving along a horizontal plane with a speed v, due to the presence
A body, of mass m, moving along a horizontal plane with a speed v, due to the presence of a friction force, stops after passing the path S. Determine the friction force, the work of this force and the separated body.
Given:
m (kilogram) is the mass of a certain body;
v (meter per second) is the speed at which the body is moving;
S (meter) – the path that the body took to stop.
It is required to determine F friction (Newton) – friction force, A (Joule) – friction force work and Q (Joule) – released heat.
Let’s find the acceleration with which the body braked:
S = a * t ^ 2/2, taking into account the fact that in this case t = v / a, we get:
S = a * (v / a) ^ 2/2 = v ^ 2 / (2 * a), from here we find that:
a = v ^ 2 / (2 * S).
Then the friction force will be equal to:
F friction = m * a = m * v ^ 2 / (2 * S).
The work of the friction force will be equal to:
A = F friction * S = m * v ^ 2 / (2 * S) * S = m * v ^ 2/2.
This work will be spent on the release of heat, that is:
Q = A = m * v ^ 2/2.
Answer: the friction force is equal to m * v ^ 2 / (2 * S), the work of the friction force and the released heat will be equal to m * v ^ 2/2.