Question

A spring, 𝑘 = 950 𝑁/m, attached to a 1.8 kg block is compressed by 20 cm and then

released. If the coefficients of friction between the block and the floor are 𝜇𝑠 = 0.52 and 𝜇𝑘 =

0.38, determine how far does the block slide on the floor.

Answer 1

By conservation of energy:

$$\frac12 kx^2=\mu_k mgL,\\\space\\ L=\frac{kx^2}{\mu_kmg}=5.7\text{ m}.$$