Answer:
1070 Hz
Explanation:
First, I should point out there might be a typo in the question or the question has inconsistent values. If the tube is 40 cm long, standing waves cannot be produced at 42.5 cm and 58.5 cm lengths. I assume the length is more than the value in the question then. Under this assumption, we proceed as below:
The insert in the tube creates a closed pipe with one end open and the other closed. For a closed pipe, the difference between successive resonances is a half wavelength
.
Hence, we have

.
The speed of a wave is the product of its wavelength and its frequency.



Answer:
Explanation:
Given
Minute hand length =16 cm
Time at a quarter after the hour to half past i.e. 1 hr 45 min
Angle covered by minute hand in 1 hr is 360 and in 45 minutes 270


(c)For the next half hour
Effectively it has covered 2 revolution and a quarter

angle turned 
(f)Hour after that
After an hour it again comes back to its original position thus displacement is same =25.136
Angle turned will also be same i.e. 
Answer:

Explanation:
Assuming that the pacific plate moved 178 km in 1.76 million years.
s = Distance = 178 km
t = Time taken = 1.76 million years
Speed is given by

The speed of the plate is 