Answer:
Explanation:
We need the power equation here:
P = W/t where W is work and is defined as
W = F*displacement.
Force is a measure in Newtons, which is also weight. We have the mass of the piano, but we need to find the weight:
w = mg so
w = 166(9.8) so
w = 1600N, rounded to the correct number of sig dig. We use that now in the power equation:
and isolating the unknown:
so
t = 5.3 seconds
Answer:
A. α = - 1.047 rad/s²
B. θ = 14.1 rad
C. θ = 2.24 rev
Explanation:
A.
We can use the first equation of motion to find the acceleration:
where,
ωf = final angular speed = 0 rad/s
ωi = initial angular speed = (30 rpm)(2π rad/1 rev)(1 min/60 s) = 3.14 rad/s
t = time = 3 s
α = angular acceleration = ?
Therefore,
<u>α = - 1.047 rad/s²</u>
B.
We can use the second equation of motion to find the angular distance:
<u>θ = 14.1 rad</u>
C.
θ = (14.1 rad)(1 rev/2π rad)
<u>θ = 2.24 rev</u>