Answer: 9.6kg
Explanation:
According to research, a person with compromised strength in his finger can apply a normal force of 6N to either side of a pinch held object like a notebook.
Since the person is holding onto to the book vertically, the force applied on both sides of the book slightly is 6 + 6 = 12N.
If the coefficient of friction of the surface between the finger and the book cover is given as 0.80.
From the relationship,
F = uR, u is the frictional force, R is the slight resultant force exerted on both side of the book.
Therefore,
F = 0.8 × 12 = 9.6N
The max mass of book this person can hold onto vertically before it slip off his finger will be derived from the formula
F = Mg
If we take acceleration due to gravity as 10m/s², and make M the subject of formula, we have
M = F/g = 9.6/10 = 0.96kg.
