<span>The cation is positively charged and has a charge twice that of the anion, for example +2.
The anion is negatively charged and in our example where the cation has a +2 charge, it must have a -1 charge.
In order for the charges to equal zero, there must be two anions: -1 x 2 = -2
So the answer is D. AX2</span>
The kinetic energy at the bottom of the swing is also 918 J.
Assume the origin of the coordinate system to be at the lowest point of the pendulum's swing. A pendulum, when raised to the highest point has potential energy since it is raised to a height h above the origin. At the highest point, the pendulum's velocity becomes zero, hence it has no kinetic energy. Its energy at the highest point is wholly potential.
When the pendulum swings down from its highest position, it gains velocity. Hence a part of its potential energy begins to convert itself into kinetic energy. If no dissipative forces such as air resistance exist, then, the law of conservation of energy can be applied to the swing.
Under the action of conservative forces, the total mechanical energy of a system remains constant.This means that the sum of the potential and kinetic energies of a body remains constant.
When the pendulum reaches the lowest point of its swing, it is at the origin of the chosen coordinate system. Its vertical displacement from the origin is zero, hence its potential energy with respect to the origin is zero. Therefore the entire potential energy of 918 J should have been converted into kinetic energy, according to the law of conservation of energy.
Thus, the kinetic energy of the pendulum at the lowest point of its swing is equal to the potential energy it had at its highest point, which is equal to <u>918 J.</u>
Answer:
r = 0.22m
Explanation:
To find the radius of the circular trajectory, you first take into account that the centripetal force of the charged particle, is equal to the electric force between the particle that is moving and the particle at the center of the orbit.
Then, you have:
(1)
m: mass of the particle = 20g = 20*10-3 kg
ac: centripetal acceleration = ?
q: charge of the particle = 5*10^-6C
Fe: electric force between the charges
The electric force is given by:
(2)
r: radius of the orbit
q': charge of the particle at the center of the orbit = -5*10^-6C
Furthermore, the centripetal acceleration is:
(3)
v: speed of the particle = 7m/s
You replace the expressions (2) and (3) in the equation (1) and solve for r:

Finally, you replace the values of all parameters in the previous expression:

The radius of the circular trajectory is 0.22m
<h3><u>Answer;</u></h3>
= 21600 Joules or 21.6 Kilo joules
<h3><u>Explanation;</u></h3>
Electrical energy is given by the formula = VIt ;
where V is the voltage in volts, I is the current in Amperes, and t is time in seconds.
Voltage = 120 volts
Current = 3 amperes
Time = 60 seconds or 1 minute
Therefore;
Electrical energy = 120 × 3 × 60
<u> = 21600 Joules or 21.6 Kilo joules</u>