Answer:
e = 50.27 give / s
Explanation:
The expression for simple harmonic motion is
x = A cos (wt + Ф)
in this case they give us the amplitude A = 3.9 cm and frequency f = 8.0 Hz
The angular and linФear variables are related
e = 2π d
e = 2π 8
e = 50.27 give / s
let's look for the constant fi
so let's find the time to have the maximum displacement
v = dx / dt
v = -A w sin (wt +Ф)
for the point of maximum displacement the speed is I think
0 = - sin (0 + Ф)
therefore fi = 0
Let's put together the equation of motion
x = 0.039 sin (50.27 t)
v = 0.039 50.27 sin (50.27 3)
v = 1.96 50 0.01355
v = 0.0266 m / s