Question

the coefficient of static friction between a 40 kg picnic table and the ground below is .43. what is the greatest horizontal force that could be exerted on the table while it remains stationary?

Answer 1

Answer:

The greatest horizontal force that can be exerted without moving the table is 168.56N.

Explanation:

The maximum friction force is determined from the coefficient of static friction as follows:

$F_{fr}=\mu\cdot F_{norm} = 0.43\cdot F_{norm}$

where the the normal force is exerted by the ground as a reaction to the weight of the table, and has same magnitude as but opposite direction to the gravitational force on the table:

$F_{fr} = 0.43\cdot 40kg\cdot 9.8 \frac{m}{s^2} = 168.56 N$

This is the maximum static force, so the friction force will be matching and opposing any horizontal force up to 168.56N.

Answer 2

The force equals the coefficient of static friction times the weight. Use gravity g=9.8 m/s^2
0.43*40*9.8=16.856 N