Question

The position of a 50 g oscillating mass is given by x(t)=(2.0cm)cos(10t−π/4), where t is in s. If necessary, round your answers to three significant figures. Determine:

the amplitude
2cm
the period
.628s
the spring constant
5N/m
the phase constant
-.785rad
the initial coordinate of the mass
1.41cm
the initial velocity
14.1 cm/s
maximum speed 20 cm/s
what's the total energy?

Answer 1

For the answer to the question above, this is the maximum displacement, the spring has only elastic potential energy.
spring is constant @ 5 N/m
maximum displacement = 2 cm = 0.02 m
elastic potential energy = 1/2 kx²
= 0.5 x 5 x 0.02²
So the answer would be
= 0.001 Joules