Question

part 3: mass of sliding object
in this part of the lab, you will try to answer the following question: what is the effect of mass on sliding friction?
prepare your experiment: which effect does mass have on the sliding friction force for a book sliding on a table?

1. form a hypothesis that answers the question for part 3 above. explain your reasoning.

hypothesis:

Explanation:

Sliding friction force \(F_f=\mu F_N\), where \(\mu\) is the coefficient of sliding friction (depends on the nature of the surfaces in contact, e.g., the book - table interface) and \(F_N\) is the normal force. For an object on a horizontal surface, \(F_N = mg\) (where \(m\) is mass and \(g\) is the acceleration due to gravity). So, as mass \(m\) increases, \(F_N\) increases. Since \(F_f=\mu F_N\) and \(\mu\) is constant (for the same surfaces), \(F_f\) should increase with mass.

Answer:

Hypothesis: As the mass of the book increases, the sliding friction force will increase. Reasoning: Sliding friction force \(F_f = \mu F_N\), and for a book on a horizontal table \(F_N=mg\). Since \(\mu\) (coefficient of sliding friction for book - table) is constant, when \(m\) (mass) increases, \(F_N\) increases, and thus \(F_f\) (sliding friction force) increases.