A gorilla drags a log across the jungle floor. The log begins at rest and accelerates at until the gorilla is moving at a fast l
ope. The coefficient of kinetic friction between the log and the mud and plants of the jungle is . Assume that friction and the gorillas pulling force remain constant the whole time. What frictional force acts on the log
We can solve this exercise using the equilibrium conditions, let's start by creating a reference system
where we call T the drag force of the gorilla, m the mass of the trunk and μ the coefficient of kinetic friction
Y axis
N- W =
N = W = mg
X axis
T - fr = 0
T = fr
the expression for the friction force is
fr = μ N
fr = μ mg
we substitute
T = μ m g
When analyzing these expressions we see that when the trunk reaches the maximum speed that the gorilla carries, the friction force is equal to the gorilla's tension
fr = T
for a specific calculation we must assign values to:
In order to calculate the unknown reaction force, we need to know that the sum of forces pointing down is equal the sum of the forces pointing up, so all forces will be in equilibrium.
