The correct answer is (A) 2.0 J
Total energy of the pendulum is the sum of its kinetic and potential energy. At the instant of time, when the pendulum is at a height <em>h</em> and has a speed <em>v, </em>Its energy is given by,

Substitute 2.0 kg for <em>m</em>, the mass of the pendulum, 9.81 m/s² for <em>g</em>, the acceleration due to gravity, 0.10 m for <em>h and 4.0 m/s for </em>v<em>.</em>

The pendulum has an initial energy of 20 J. the energy lost is given by,

Thus, the energy lost by the pendulum is (A) 2.0 J
Answer:
Lower energy shell which will be nearer to the nucleus.
Explanation:
When electron move from one energy level to another, an electron must gain or lose just the right amount of energy.
When atoms releases energy, electrons move into lower energy levels. The electrons in the shells aways from the nucleus have more energy as compared to the electrons in the nearer shells.
Electrons with the lowest energy are found closest to the nucleus, where the attractive force of the positively charged nucleus is the greatest. Electrons that have higher energy are found further away
Answer:
a).
b).
Explanation:
a).
The work of the spring is find by the formula:

So knowing the work can find the constant K'

Solve for K'


b).
The force of the spring realice a motion so using the force and knowing the accelerations can find the mass




Answer:
each resistor is 540 Ω
Explanation:
Let's assign the letter R to the resistance of the three resistors involved in this problem. So, to start with, the three resistors are placed in parallel, which results in an equivalent resistance
defined by the formula:

Therefore, R/3 is the equivalent resistance of the initial circuit.
In the second circuit, two of the resistors are in parallel, so they are equivalent to:

and when this is combined with the third resistor in series, the equivalent resistance (
) of this new circuit becomes the addition of the above calculated resistance plus the resistor R (because these are connected in series):

The problem states that the difference between the equivalent resistances in both circuits is given by:

so, we can replace our found values for the equivalent resistors (which are both in terms of R) and solve for R in this last equation:

Answer:
2,800 n
Explanation:
hope this helps, have a nice day/night! :D