Tenemos los siguientes datos
<img src="https://tex.z-dn.net/?f=m%3D8617%5C%2Ckg%5C%5C%20h%3D52%5C%2Cm%5C%5C%20E_%7Bp%7D%3DE_%7Bc%7D" />
Puesto que queremos encontrar <img src="https://tex.z-dn.net/?f=%20v" /> y tenemos la condición de que <img src="https://tex.z-dn.net/?f=E_%7Bp%7D%3DE_%7Bc%7D" />, entonces :
<img src="https://tex.z-dn.net/?f=E_%7Bp%7D%3Dmgh%5C%5C%20E_%7Bp%7D%3D%288617%5C%2Ckg%29%289.81%5C%2Cm%2Fs%5E%7B2%7D%29%28%2852%5C%2Cm%29%5C%5C%20E_%7Bp%7D%3D4395704.04%5C%2Ckg.m%5E%7B2%7D%2Fs%5E%7B2%7D%3D4395704.04%5C%2CJ" />
Luego :
<img src="https://tex.z-dn.net/?f=E_%7Bc%7D%3D%5Cfrac%7Bmv%5E%7B2%7D%7D%7B2%7D%5C%5C%20mv%5E%7B2%7D%3D2E_%7Bc%7D%5C%5C%20v%5E%7B2%7D%3D%5Cfrac%7B2E_%7Bc%7D%7D%7Bm%7D%5C%5C%20v%3D%5Csqrt%7B%5Cfrac%7B2E_%7Bc%7D%7D%7Bm%7D%7D" />
Sustituyendo :
<img src="https://tex.z-dn.net/?f=v%3D%5Csqrt%7B%5Cfrac%7B2%284395704.04%5C%2CJ%29%7D%7B8617%5C%2Ckg%7D%7D%5C%5C%20v%3D31.94%5C%2Cm%2Fs" />
Saludos.