Answer:
1) a) I₁ = 0.2941 kg m², b) I₂ = 0.2963 kg m², c) I_{total} = 0.5904 kg m²
3) α = 6.31 10⁶ rad / s²
Explanation:
1) The moment of inertia for bodies with high symmetry is tabulated, for a divo with an axis passing through its center is
I = ½ m r²
a) moment of inertia of the upper disk
I₁ = ½ m₁ r₁²
I₁ = ½ 1,468 0.633²
I₁ = 0.2941 kg m²
b) upper aluminum disc moment of inertia
I₂ = ½ m₂ r₂²
I₂ = ½ 1.479 0.633²
I₂ = 0.2963 kg m²
c) the moment of inertia is an additive scalar quantity therefore
I_{total} = I₁ + I₂
I_{total} = 0.2941 + 0.2963
I_{total} = 0.5904 kg m²
3) ask the value of the angular acceleration, that is, the second derivative of the angle with respect to time squared
indicate the angular velocity of the system w = 400 rev / s
Let's reduce the SI system
w = 400 rev / s (2π rad / rev) = 2513.27 rad / s
as the system is rotating we can calculate the centripetal acceleration
a = w² R
a = 2513.27² 0.633
a = 3.998 10⁶ m / s²
the linear and angular variable are related
a = α r
α = a / r
α = 3.998 10⁶ / 0.633
α = 6.31 10⁶ rad / s²
Answer:
A
Explanation:
There is a mechanical advantage in this system....
she only needed 100 N to lift 500 N
1:5 she lifted it 2 meters, so if there WAS NO friction, she would have to pull in 5 x 2 = 10 meters
but there IS friction so she must have pulled in MORE than 10 m
Answer:
a. 7.89 Ω, 1.14 W
b. By a factor of 2; The batteries would heat up.
Explanation:
a. Using Ohm's law, we have that Voltage, V, is directly proportional to Current, I, with the constant of proportionality being Resistance, R. Mathematically:
V = IR
The voltage of the two batteries would be:
V = V1 + V2 = 1.5 + 1.5 = 3.0 V
The current is 380 mA = 0.38 A
Hence, the Resistance, R, will be:
R = 7.89 Ω
Power is given as:
P = IV
P = 3 * 0.38
P = 1.14 W
b. If the batteries are now 4, the new voltage will be:
V = 4 * 1.5
V = 6 V
Power becomes:
P = 0.38 * 6
P = 2.28 W
Comparing with Power in (a) above, we see that the new Power is double the value of the former Power. Hence, the Power has increased by a factor of 2.
It is not advisable to use double the number of batteries to power a flashlight because it would cause the batteries to heat up and thereby, leak or in the worst case scenario, blow up. This could be damaging to the flashlight.
Answer: Addition of
salt bridge
To generate a standard
electromotive force, an addition of salt bridge is essential to help maintain
electrical neutrality within the internal circuit and prevent the cell from
rapidly running its reaction to equilibrium.
In addition, salt bridge contains potassium
sulfate, an inert electrolyte where its ions will diffuse into the separate half-cells
to stabilize the building charges at the electrodes and produce electricity.
