Can we see the diagram? Thanks.
The formation of lactic acid in human muscles is closely associated with intense exertion or activity, during which aerobic respiration that uses oxygen to produce energy cannot be able to match the demand of energy by the muscles.
The muscles therefore resort to anaerobic respiration for energy where pyruvate becomes a makeshift hydrogen acceptor rather than oxygen as happens in aerobic respiration.
Pyruvate accepts a hydrogen from NADH and becomes reduced to lactate or lactic acid while NADH is oxidized to NAD
which is crucial in the formation of energy that is then stored in the form of ATP which is used to re-fuel the muscles to keep them going.
Answer:
miu = 0.31
Explanation:
The friction force is defined as the product of the normal force by the coefficient of friction.

where:
f = friction force = 3 [N]
miu = friction coefficient
N = normal force [N]
The normal force on a horizontal surface can be calculated by means of the product of mass by gravity.
where:
m = mass = 1 [kg]
g = gravity acceleration = 9.81 [m/s²]

![N= 9,81 [N]](https://tex.z-dn.net/?f=N%3D%209%2C81%20%5BN%5D)
Now replacing in the equation above, we can find the friction coefficient.
