Adrum can begin to vibrate at its natural frequency without being struck through:

a. refection

b. diffraction

c. refraction

d. resonance

answer is

Explanation:

If an external vibration matches the drum's natural frequency, it will induce the can to vibrate. This is an example of resonance.

It is analogous to pumping your legs in synchronization with a swing's natural frequency.

consider the reaction below.

 no rx

at 500 k, the reaction is at equilibrium with the following concentrations.

[pci5]= 0.0095 m

[pci3] = 0.020

[ci2] = 0.020 m

what is the equilibrium constant for the given reaction?

0.042

0.42

2.4

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