Answer:
64 J
Explanation:
W = ΔPE
W = mgΔh
W = (130 kg) (9.8 m/s²) (0.050 m)
W = 64 J
Answer:
a) m=20000Kg
b) v=0.214m/s
Explanation:
We will separate the problem in 3 parts, part A when there were no coals on the car, part B when there is 1 coal on the car and part C when there are 2 coals on the car. Inertia is the mass in this case.
For each part, and since the coals are thrown vertically, the horizontal linear momentum p=mv must be conserved, that is, , were each velocity refers to the one of the car (with the eventual coals on it) for each part, and each mass the mass of the car (with the eventual coals on it) also for each part. We will write the mass of the hopper car as , and the mass of the first and second coals as and respectively
We start with the transition between parts A and B, so we have:
Which means
And since we want the mass of the first coal thrown () we do:
Substituting values we obtain
For the transition between parts B and C, we can write:
Which means
Since we want the new final speed of the car () we do:
Substituting values we obtain
Answer:
4 photovoltaic cells are required to meet monthly energy consumption of the cabin.
Explanation:
Let suppose that PV generation system produces energy at constant energy, the number of photovoltaic system to meet energy consumption of the cabin is:
(1)
Where:
- Energy consumption of the PV system, in kilowatt-hours.
- Power generation of the PV cell, in kilowatts.
- Working times, in hours.
If we know that , and , then the number of photovoltai cells is:
4 photovoltaic cells are required to meet monthly energy consumption of the cabin.
Answer:
use the formula
Explanation:
F = 1/ T
where F stands for frequency and T stands for period
sub in 3 Hz into frequency
3 = 1/T
0.333 = T
or in a fraction form
1/ 3
hope this helps
Answer:
D) The capacitor will pull the material into the space between the plates, and the potential energy stored between the plates of the capacitor will decrease by a factor of 3
Explanation:
points to note
A) inserting a material with dielectric constant of 3 between the plates means that the capacitance C will increase by 3.
B) Since the battery is disconnected, the potential difference V between plate will not remain constant.
C) increasing the capacitance reduces the potential difference across the plate, and from C = Q/V it can be seen that the charges on the plate remains constant.
From the proof in the image below, the reduction in the potential energy of the capacitor is due to the energy used by the capacitor to pull the dielectric material into the space.