Answer:
<em>The correct choice is D. Its gravitational potential energy must increase</em>
Explanation:
<u>Conservation of Mechanical Energy</u>
The total amount of mechanical energy, in a closed system in the absence of dissipative forces like friction or air resistance, remains constant.
This means that energy cannot disappear or appear and that potential energy can become kinetic energy or vice versa.
In a closed system like a pendulum, two types of energies are considered: Gravitational potential (U) and kinetic (K). Thus, the sum of both energies must remain constant in time.
Suppose the pendulum is at a state where U=150 J, and K=350 J. The total mechanical energy is:
M = 150 J + 350 J = 500 J
If the kinetic energy decreases to a new value, say K = 200 J, then the gravitational potential must increase to compensate for this new condition, that is: U = 300 J
The correct choice is D. Its gravitational potential energy must increase
Answer:
0.028 M.
Explanation:
NOTE: This question is a chemistry question. However, the answer to the question can be obtained as shown below:
We'll begin by calculating the number of mole in 2.52 g of oxalic acid, C₂H₂O₄. This can be obtained as follow:
Mass of C₂H₂O₄ = 2.52 g
Molar mass of C₂H₂O₄ = (2×12) + (2×1) + (4×16)
= 24 + 2 + 64
= 90 g/mol
Mole of C₂H₂O₄ =?
Mole = mass / molar mass
Mole of C₂H₂O₄ = 2.52 / 90
Mole of C₂H₂O₄ = 0.028 mole
Finally, we shall determine the molarity of the solution. This can be obtained as follow:
Mole of C₂H₂O₄ = 0.028 mole
Volume = 1 L
Molarity =?
Molarity = mole / Volume
Molarity = 0.028 / 1
Molarity = 0.028 M
Therefore, the molarity of the solution is 0.028 M.
The method to choose depends on what information you have, and
on what you can measure. Here are a few possible methods:
-- Measure the period. Start your clock when one peak
of the wave passes you. Stop the clock when the next
peak passes you. The time between the two peaks is
the wave's period.
-- Divide the wave's wavelength by its speed. That quotient
is the wave's period.
-- Use an electronic frequency meter to measure the wave's
frequency. Then take its reciprocal (divide ' 1 ' by it). The
result is the wave's period.
