Answer Happy

Pauline has a coil spring with a spring constant of 31 N/m, which is 10.0 cm long without load. With that spring she pulls a block of 100 g across the table. The block accelerates in 0.42 s from 3.0 m/s to 6.4 m/s. The spring is 13.0 cm long when pulled. A) Calculate the sliding friction force that the table exerts on the block. Pauline performs the same experiment with a stiffer spring. This spring is also 10.0 cm long when unloaded. She pulls the same block across the table and makes sure that the spring is 13.0 cm long. B) Explain whether the acceleration of the block is greater or less than in the situation in question a.