We know, Period = 1/frequency = 1/20 sec.
So, your final answer is 0.05 sec
Hope this helps!
I think the answer to your question is that:
There is chemical energy being produced (by the water) and that causes the base of iron to absorb the heat. Then when the heated base of the iron is placed onto the shirt, the heat flattens the wrinkles on it.
B. Both of these types of lenses have the ability to produce real images.
The answer would be 9,940 K is the temperature of Sirius B.
