Question

Una masa conectada a un resorte ejecuta MAS. Cuando la masa está en su desplazamiento máximo desde la posición de equilibrio, su velocidad instantánea

a)Es máxima.

b)Es menor que máxima, pero no cero.

c)Es cero.

d)No puede determinarse sin la información de la masa.

e)No puede determinarse sin la información de la constante del resorte.

Answer 1

Given that

the mass which is attached to the spring is in SHM and at the maximum displacement from the equilibrium position so

by conservation of energy of the system

as the mass is at maximum position from equlibrium the elastic potential energy gradully increases from the equilibruim as it is moving away from equlibrium and becomes maximum and the kinetic energy of the system(mass) gradually decreases, becomes zero at extream end, so momentarily it comes to rest.

so the instantaneous velocity become zero

the velocity would be maximum at equilibrium position only not at extream end

by conservation of energy we can say the velocity , no need of the mass , spring constnat etc

so the answer is option C

here is the energy equation  

total energy of the system is constant  

E = U+K

E = 0.5*k*x^2+0.5*m*v^2

E = 0.5*k*x^2 at extream (maximum position from equilibrium)

and

E = 0.5*m*v^2 , when x= 0 m at equilibrium position