Question

Blocks m (15 kg) and M (90 kg) need a minimum force F to maintain m against M. The surface under M lacks friction. What is the static friction coefficient between m and M?

a) 0.1
b) 0.2
c) 0.3
d) 0.4

Answer 1

The coefficient of static friction between blocks m and M is 0.0112.

Step-by-step explanation:

The formula to calculate the minimum force required to maintain block m against block M is Fmin = µs N, where µs is the coefficient of static friction and N is the normal force.

In this case, since the surface under M lacks friction, the normal force N is equal to the weight of block M, which is given by N = Mg. Therefore, the minimum force Fmin = µs Mg.

With the given values of M (90 kg) and F (10 N), we can calculate the coefficient of static friction (µs) by rearranging the equation as µs = Fmin / Mg.

Using the given values, the coefficient of static friction is: µs = 10 N / (90 kg * 9.8 m/s²) = 0.0112.