Step-by-step explanation:
It is given that,
Mass of the block, m = 8.15 kg
Time, t = 0.521 s
It is pulled through a distance of 3.62 m, s = 3.62 m
Initially, u = 0
Spring constant of the spring, k = 415 N/m
We need to find the stretching in the spring. Firstly, we will find the acceleration of the block. It can be calculated using second equation of motion as :




Now, the force due to this acceleration is balanced by the force in spring as :



x = 0.52 meters
So, the spring is stretched by 0.52 meters. Hence, this is the required solution.