Answer:
Explanation:
STEP 1
<u>Given</u>
Radius of cylinder = r = 25cm, 2.5m
mass = 27kg
cylinder is mounted so as to rotate freely about a horizontal axis that is parallel to and 60cm to the central logitudinal axis of the cylinder
height = 0.6m
<u>part 1</u>
The cylinder is mounted so as to rotate freely about a horizontal axis tha is paralle to 60cm from the central longitudinal axis of then cylinder. The rotational inertia of the cylinder about the axis of rotation is given by
<em>I = Icm + mh²</em>
<em>∴ I = 1/2mr² + mh² = 1/2x27x (0.5)² + 20 x (0.6)²</em>
<em>I=13.09kg.m²</em>
where
<em>I</em>cm is the rotational inertia of the cylinder about its central axis
m is the mass of the cylinder
h is the distance between the axis of the rotation and the central axis of the cylinder
r is the radius of the cylinder
<em> </em><em> I=13.09kg.m²</em>
<em>part2</em>
<em>from the conservation of the total mechanical energy of the meter stick, the change in gravitational potential energyof the meter stick plus the change in kinetic energy must be zero</em>
<em>Δk + Δu = 0</em>
<em>1/2 </em>I(w²-w²) = Ui-Uf
1/2 x 13.09w² = mgh
∴w=√20 x 9.8 x 0.6/(1/2 x 13.09) =117.6/6.5
w=18.09rad/s
Answer:
C
Explanation:
To melt the alcohol
Heat needed = M . L = 2 . 25 = 50 kcal
To warm up the alcohol
Heat needed = M . sp. ht. . ∆t = 2 . 0.6 . 100 = 120 kcal
Total heat needed = 170 kcal
Assuming that 0.6 kcal/ kg / ˚C is the specific heat and that the answer is wanted in kcal ( a rather odd unit to be in use here.)
C. endothermic
An endothermic process takes heat from the surroundings while an exothermic process gives out heat to the surroundings.
If you, for example, poured it onto a wide cup with a volume equal to the total volume of the sand particles, the sand would not spread out to fill the container but would bunch up together in the middle.
<span>An object roating at one revokution per second has an angular velocity of 360 degrees per second or 2pi radians per second. This is found by taking the number of revolutions over a period of time and than dividing by the chosen period of time to get the velocity. There are 360 degrees or 2pi radians in one revolution.</span>