Answer:
The stress is calculated as
Solution:
As per the question:
Length of the wire, l = 75.2 cm = 0.752 m
Diameter of the circular cross-section, d = 0.560 mm =
Mass of the weight attached, m = 25.2 kg
Elongation in the wire,
Now,
The stress in the wire is given by:
(1)
Now,
Force is due to the weight of the attached weight:
F = mg =
Cross sectional Area, A =
Using these values in eqn (1):
Answer:
The time taken by the brick to hit the ground, t = 0.84 s
Explanation:
Given that,
A brick falls from a height, h = 3.42 m
The initial velocity of the brick is zero.
Since the brick is under free-falling. The time equation of a free-falling body when the displacement is given is
t =
where,
h - height from surface in meters
g - acceleration due to gravity
on substituting the values in the above equation,
t =
= 0.84 s
Hence, time taken by the brick to hit the ground is t = 0.84 s