Answer:
Step-by-step explanation:
Given
at certain point displacement and velocity is 0.345 m and 0.54 m/s
Therefore Potential and Kinetic Energy associated is
![U=(1)/(2)kx^2](https://img.qammunity.org/2020/formulas/physics/middle-school/xov4vaxr3ylfw4jh9jsmxs04vfir01zz7x.png)
![U=(1)/(2)* 9.8* (0.345)^2](https://img.qammunity.org/2020/formulas/physics/high-school/sbxt22kmo7qv4ufvcs5n0blone6yz9kbx6.png)
![U=0.583 J](https://img.qammunity.org/2020/formulas/physics/high-school/osqu31e1gzvz40xbomnmub1yl1ryfl5wv5.png)
Kinetic Energy
![K=(1)/(2)mv^2](https://img.qammunity.org/2020/formulas/physics/middle-school/c6fs3acuplloc3whu5cpc8ui63cnl7ur39.png)
![k=(1)/(2)* 1.2* (0.54)^2=0.174 J](https://img.qammunity.org/2020/formulas/physics/high-school/z3ownl20yesx9jkfjd1k20dna65r1phmd5.png)
Total Energy
![T=U+K=0.583+0.174=0.757 J](https://img.qammunity.org/2020/formulas/physics/high-school/w278qijynn8uoglqwlltudw0lwu43go7en.png)
Total Energy is conserved hence at maximum displacement all energy will be Potential energy
![T=(1)/(2)kA^2](https://img.qammunity.org/2020/formulas/physics/high-school/apd62jgkyp7qvxb3xjigj9gzu21abxqry3.png)
where A=maximum displacement
![0.757=(1)/(2)* 9.8* A^2](https://img.qammunity.org/2020/formulas/physics/high-school/o4vsg86hll9hmyr1alrcha4ct116hrz29f.png)
![0.1544=A^2](https://img.qammunity.org/2020/formulas/physics/high-school/8wgzrtx5nt6jmmtou8zy6xd0nkcf83bbym.png)
![A=0.393 m](https://img.qammunity.org/2020/formulas/physics/high-school/u0djfxejem4goqr4xyx4u00z2ygg85m5n0.png)
Maximum speed occurs at equilibrium Position where Potential Energy is zero
thus
![T=(1)/(2)mv^2](https://img.qammunity.org/2020/formulas/physics/high-school/utndv6yaof8w6pt8wdpx77gxe9uai7b2o2.png)
![0.757=(1)/(2)* 1.2* v_(max)^2](https://img.qammunity.org/2020/formulas/physics/high-school/ieq7d4t8lif0qkyitquzibr75hkz2nowal.png)
![v_(max)=1.123 m/s](https://img.qammunity.org/2020/formulas/physics/high-school/s8fwy9u1nkcndmbv177f6uqfidix7cj76t.png)
(c)When block is at 0.2 m from Equilibrium speed then its Potential Energy is
![U=(1)/(2)kx^2=(1)/(2)* 9.8* (0.2)^2=0.196 J](https://img.qammunity.org/2020/formulas/physics/high-school/u2fotxkvv51zo6ini17k52qkzoxk62zmk7.png)
![T=U+K](https://img.qammunity.org/2020/formulas/physics/high-school/ji72py6d48r1g9p0egpd0ebl52dos9helg.png)
![K=0.757-0.196=0.561 J](https://img.qammunity.org/2020/formulas/physics/high-school/e695lua5nj6szm0dklw6z7ihqa70l7tztb.png)
![K=(1)/(2)mv^2](https://img.qammunity.org/2020/formulas/physics/middle-school/c6fs3acuplloc3whu5cpc8ui63cnl7ur39.png)
![0.561=(1)/(2)* 1.2* v^2](https://img.qammunity.org/2020/formulas/physics/high-school/d84u741f2vrf259bw7mls5d7x0cnqhkzfa.png)
![v=0.966 m/s](https://img.qammunity.org/2020/formulas/physics/high-school/enphsboq764i1xw6z39vielfvl17lvzx50.png)