Explanation:
When an object moves in a circular path, it will have circular acceleration. Its magnitude of acceleration is given by :
Since,
T is the time period
R is the radius of the circular path
To increase the centripetal acceleration bu a factor of 1.5 or 3/2, radius of circle must be increase by a factor of 6 and T is increased by a factor of 2 such that,
R'=6R and T'=2T
So,
Hence, this is the required solution.
Answer:
The critical stress required for the propagation of an initial crack = 21.84 M pa
Explanation:
Given data
Modulus of elasticity E = 225 ×
Specific surface energy for magnesium oxide is = 1
Crack length (a) = 0.3 mm = 0.0003 m
Critical stress is given by =
-------- (1)
⇒ 2 E = 2 × 225 ×
× 1 = 450 ×
⇒ a = 3.14 × 0.0003 = 0.000942
⇒ Put these values in equation 1 we get
⇒ =
⇒ = 4.77 ×
⇒ = 2.184 ×
⇒ = 21.84
⇒ = 21.84 M pa
This is the critical stress required for the propagation of an initial crack.