A: A billiard ball (mass, M and radius R) and a cylindrical aluminum rod (Mass 3
ID: 1344212 • Letter: A
Question
A: A billiard ball (mass, M and radius R) and a cylindrical aluminum rod (Mass 3M, radius 3R) are rolled on a level surface. Compare the moments of inertia. Iball/Iroll is ______.
B: An I-phone is flipped so that it rotates about its long axis with an angular momentum L. The I-phone is then flipped with same angular momentum L about its short axis.
The moment of inertia of the I-phone flipped along the long axis is I = 6 kgm2 and it rotates at 6 rad/s . The moment of inertia of the I-phone flipped along the short axis is 4 kgm2.
C: At a depth h = 67 m below the surface of the ocean, the absolute pressure Pabsolute = ______ atm. (Note: The density of seawater is 1.025 x 103 kg/m3.)
t = ____ s to stop the wheel
F: A 14,302N vehicle is to be lifted by a hydraulic lift which has an output piston of diameter d =89cm.
The minimum force on the small piston to lift the 8 cm diameter input piston is _____ N?
Explanation / Answer
A) .
Iball = 2MR^2 / 5
Iroll = (3M) (3R)^2 = 27MR^2
Iball / Iroll = (2MR^2 / 5) / (27MR^2 ) = 0.0148
B) I1 w1 = I2 w2
6 x 6 = 4 w
w = 9 rad/s
C) P = row* g * h = (1.025 x 10^3 x 9.81 x 67) = 673701.75 Pa
1 atm = 101325 Pa
P = 6.65 atm
D) L = torque x time
291 = 58t
t = 5.02 sec
F) P = F/A = cosntant
14320 / (pi x (89/2)^2) = F / (pi x 4^2)
F = 115.56 N