Answer:
78.4 KN/m
Explanation:
Given
mass of person 'm' =80 kg
car dips about i.e spring stretched 'x'= 1 cm => 0.01m
acceleration due to gravity 'g'= 9.8 m/s^2
as we know that,in order to find approximate spring constant we use Hooke's Law i.e F=kx
where,
F = the force needed
x= distance the spring is stretched or compressed beyond its natural length
k= constant of proportionality called the spring constant.
F=kx
---> (since f=mg)
mg=kx
k=(mg)/x
k=(80 x 9.8)/ 0.01
k=78.4x
k=78.4 KN/m
To solve this exercise it is necessary to take into account the concepts related to Tensile Strength and Shear Strenght.
In Materials Mechanics, generally the bodies under certain loads are subject to both Tensile and shear strenghts.
By definition we know that the tensile strength is defined as

Where,
Tensile strength
F = Tensile Force
A = Cross-sectional Area
In the other hand we have that the shear strength is defined as

where,
Shear strength
Shear Force
Parallel Area
PART A) Replacing with our values in the equation of tensile strenght, then

Resolving for F,

PART B) We need here to apply the shear strength equation, then



In such a way that the material is more resistant to tensile strength than shear force.
Answer:
h=12.41m
Explanation:
N=392
r=0.6m
w=24 rad/s

So the weight of the wheel is the force N divide on the gravity and also can find momentum of inertia to determine the kinetic energy at motion


moment of inertia

Kinetic energy of the rotation motion

Kinetic energy translational

Total kinetic energy

Now the work done by the friction is acting at the motion so the kinetic energy and the work of motion give the potential work so there we can find height

Answer:
Option A
Solution:
As per the question:
The distance covered by the woman in the North direction, d = 3000 m
Time taken to travel in North direction, t = 25.0 min = 1500 s
Velocity of woman in the south direction, v = 2.00 m/s
Time taken in the south direction, t' = 60.0 min = 3600 s
Now,
The distance covered in the south direction, d' = vt' = 
Now, the total displacement is given by:
D = d' - d = 7200 - 3000 = 4200 m in South
(a) Average velocity of the woman in the whole journey is given by:

≈ 0.824 m/s South