Answer:
a) the rotational speed of the clay is 3.45 rad/s
b) the value of A in the equation of motion is 0.15 m
c) the value of ϕi is 90° or π/2 rad.
Explanation:
Given that;
Revolution per minute rpm = 33( 1/3) = 100/3
The frequency f = 100 / 3(60) = 0.55 Hz
a)
Rotational speed W = 2πf
we substitute
W = 2π × 0.55
W = 3.45 rad/s
Therefore, the rotational speed of the clay is 3.45 rad/s
b)
given equation; y(t)=Asin(ωt+ϕi)
given that radius = 0.15 m
y(t)=(0.2)sin(ωt+ϕi)
Therefore, the value of A in the equation of motion is 0.15 m
c)
since y(t) has the maximum value at t =0
so at t=0
y(0) = (0.15)sin(ω(0)+ϕi)
= 0.15sin(ϕi)
this will give maximum value when ϕi = 90°
so
y(0) = (0.15)sin(ω(0)+ϕi)
= 0.15sin(90°)
= 0.15
hence, the value of ϕi is 90° or π/2 rad.