answer: i'm not sure which is which for i get confused on it all the time but i can tell you that the answer lies with the convex and concave devices. i hope this you. have a good day and best of luck to you!
potential energy is directly proportional to height.
more height = more potential energy.
greatest increase in height = greatest increase in potential energy
where are the points with the greatest increase in height ?
has to be c-e or d-e .
t = 0.25 seconds ( option b)
Assuming that there is no energy loss due to friction , then the total energy E of the system is conserved and is equal to the sum of kinetic K and potential energy V:
E= K + V
V= 1/2*k*x² , k= spring constant
K= 1/2*m*v² , v= velocity
but x = 10 sin (π*t)
when the particle reaches its maximum amplitude (x=L=10) , it has no velocity ( can be proven by finding v=dx/dt at t=1/2 for example) , then V=0 and E=K max, then
E=Kmax = 1/2*k*L²
when the kinetic energy is equal to the potential energy K=V , then
E=K+V= K+K=2K = 2*1/2*k*x² = k*x²
since also E=1/2*k*L²
x= L/√2 =10 /√2
x=10 sin (π*t) = 10 /√2 → t = (1/ π) [sin ⁻¹ (1/√2)] = 0.25
t = 0.25 seconds