Period, the Pendulum and Frequency

[alwysnforevr002]

If a pendulum is adjusted so that its frequency changes from 10 Hz to 20 Hz, its period will change from n seconds to what?
a. n/4 seconds.
b. n/2 seconds.
c. 2n seconds.
d. 4n seconds

 

[Kurdt]

what are your thoughts so far?

 

[alwysnforevr002]

Well i think they are inversly related therefore i think the answer should be n/2.

 

[Kurdt]

Yes frequency is 1/t so double frequency half the time.

 

[alwysnforevr002]

Great! Thank You so much. If you have a moment I have another question.

A 0.10 kg piece of copper at an initial temperature of 95°C is dropped into 0.20 kg of water contained in a 0.28 kg aluminum calorimeter. The water and calorimeter are initially at 15°C. What is the final temperature of the system when it reaches equilibrium?

For this problem i can only find an equation that solves for the intial temperature. I tried to solve this equation and i got 255 degress C which i know has to be incorrect because if the piece of copper starts at 95 degrees celsius and is put in cooler water it is not going to get hotter but colder.
If you cant/do not wish to answer this question that is perfectly fine but thank you again for you reassurance on my last question!

 

[Gokul43201]

alwys,

1. Try and post questions on different topics in different threads.

2. Read the forum posting guidelines (see my signature for the link). We can only help you if you show your effort first. We will not provide answers to multiple choice questions.

3. For this problem, it looks like you may have made a calculation/arithmetic arror. We can't tell you where the error is unless you show us the steps you took.