Answer:
The compression is
![x = 0.05 \ m](https://img.qammunity.org/2021/formulas/physics/college/pewj4v5pno3uaym89fld6tedtm5iejh99i.png)
Step-by-step explanation:
From the question we are told that
The first velocity is v
The compression of the spring is
![d = 1.0 \ cm = 0.01 \ m](https://img.qammunity.org/2021/formulas/physics/college/nh5kylamk1lvaevfiu5ngzqqlzgd20udmd.png)
The second velocity is 4v
Generally according to the law of energy conservation
The kinetic energy of the block is equal to the energy stored in the spring that is
![(1)/(2) * m* v^ 2 = (1)/(2) * k * d^2](https://img.qammunity.org/2021/formulas/physics/college/hvj3fhm7qaxl45hx6j51zbdft1i4v0eg4q.png)
For first speed
![m* v^ 2 = k * 0.01^2](https://img.qammunity.org/2021/formulas/physics/college/ylw7tgqurtv8m8as23fbulr1m1p0rgu75k.png)
=>
![m* v^ 2 = k * 0.0001](https://img.qammunity.org/2021/formulas/physics/college/dnrb6570t5ahw3b5r0dyypsg80zh5n1jjr.png)
=>
![k = ( m v^2 )/( 0.0001)](https://img.qammunity.org/2021/formulas/physics/college/csqj6r7jxjkn6b0pbv54qiwfth7pdmo614.png)
For second speed
![(1)/(2) * m* (5v)^ 2 = (1)/(2) * k * x^2](https://img.qammunity.org/2021/formulas/physics/college/m5r8al1vovb8n1jzbtgdfau142nemgirck.png)
=>
![12.5mv^2 = 0.5 k x^2](https://img.qammunity.org/2021/formulas/physics/college/aikrurhcewdgb7v446isrjqk1ys58km7am.png)
substituting for k
=>
![12.5mv^2 = 0.5 ((mv^2)/(0.0001) ) x^2](https://img.qammunity.org/2021/formulas/physics/college/jzt93on1d8gnju24yb27u8ax6jrklyghsi.png)
=>
![12.5 = 5000x^2](https://img.qammunity.org/2021/formulas/physics/college/730pzo8d6sclsdkj9wy62gcye3pio1y19v.png)
=>
![x = 0.05 \ m](https://img.qammunity.org/2021/formulas/physics/college/pewj4v5pno3uaym89fld6tedtm5iejh99i.png)