The angular speed of a rotating platform changes from
ω
0
=
2.8

r
a
d
/
s
to
ω
=
8.8

r
a
d
/
s
at a constant rate as the platform moves through an angle
Δ
θ
=
5.5

r
a
d
i
a
n
s
. The platform has a radius of R = 28 cm.

(a) Calculate the angular acceleration of the platform.

(b) Calculate the tangential acceleration of a point on the surface of the platform at the outer edge.

(c) Calculate the final centripetal acceleration of a point at the outer edge of the platform.

Arigid tank is divided into two equal parts by a partition. one part of the tank contains 3 kg of compressed liquid water at 400 kpa and 60°c while the other part is evacuated. the partition is now removed, and the water expands to fill the entire tank. determine the entropy change of water during this process, if the final pressure in the tank is 40 kpa. use steam tables.

Specific heat refers to the amount of heat required to change 1 gram of a substance by degree(s) celsius

Cells in the nervous system have a potential difference of 70 mv across the cell membrane separating the interior of the cell from the extracellular fluid. this potential difference is maintained by ion pumps that move charged ions across the membrane. is this an emf? select the correct answer and explanation. 1)no. the ion pumps cannot separate charges; thus, they cannot create a potential difference. 2)yes. the ion pumps cannot separate charges, but they still can create a potential difference. 3)yes. the ion pumps can actively separate charge; thus, they can create a potential difference. 4)no. the ion pumps can separate charges, but they cannot create a potential difference.