Answer:
minimum length of a surface crack is 18.3 mm
Explanation:
Given data
plane strain fracture toughness K = 82.4 MPa m1/2
stress σ = 345 MPa
Y = 1
to find out
the minimum length of a surface crack
solution
we will calculate length by this formula
length = 1/π ( K / σ Y)²
put all value
length = 1/π ( K / σ Y)²
length = 1/π ( 82.4 / 345× 1)²
length = 18.3 mm
minimum length of a surface crack is 18.3 mm
The period is 1/5 second, and the frequency is 5 Hz.
Explanation:
Let's start by reviewing some definitions about waves:
- The period of a wave is the time taken for the wave to make one complete cycle. It is indicated with T and it is measured in seconds (s)
- The frequency of a wave is the number of complete cycles made by the wave in one second. It is indicated with f and it is measured in Hertz (Hz). It is equal to the reciprocal of the period:
where f is the frequency and T is the period.
In this problem, we have a wave that passes a given point five time per second. This means that the number of oscillations per second is five, and so its frequency is:
It follows than the period of the wave is:
Therefore, the correct statement is
The period is 1/5 second, and the frequency is 5 Hz.
Learn more about waves, frequency and period:
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Answer:
T = 692.42 N
Explanation:
Given that,
Mass of hammer, m = 8.71 kg
Length of the chain to which an athlete whirls the hammer, r = 1.5 m
The angular sped of the hammer,
We need to find the tension in the chain. The tension acting in the chain is balanced by the required centripetal force. It is given by the formula as follows :
So, the tension in the chain is 692.42 N.