Answer:
Moment of inertia of the system is 289.088 kg.m^2
Explanation:
Given:
Mass of the platform which is a uniform disk = 129 kg
Radius of the disk rotating about vertical axis = 1.61 m
Mass of the person standing on platform = 65.7 kg
Distance from the center of platform = 1.07 m
Mass of the dog on the platform = 27.3 kg
Distance from center of platform = 1.31 m
We have to calculate the moment of inertia.
Formula:
MOI of disk = 
Moment of inertia of the person and the dog will be mr^2.
Where m and r are different for both the bodies.
So,
Moment of inertia
of the system with respect to the axis yy.
⇒ 
⇒ 
⇒ 
⇒
The moment of inertia of the system is 289.088 kg.m^2
Answer:
The pressure exerted by the woman on the floor is 1.9061 x 10⁷ N/m²
Explanation:
Given;
mass of the woman, m = 55 kg
diameter of the circular heel, d = 6.0 mm
radius of the heel, r = 3.0 mm = 0.003 m
Cross-sectional area of the heel is given by;
A = πr²
A = π(0.003)²
A = 2.8278 x 10⁻⁵ m²
The weight of the woman is given by;
W = mg
W = 55 x 9.8
W = 539 N
The pressure exerted by the woman on the floor is given by;
P = F / A
P = W / A
P = 539 / (2.8278 x 10⁻⁵ )
P = 1.9061 x 10⁷ N/m²
Therefore, the pressure exerted by the woman on the floor is 1.9061 x 10⁷ N/m²
Based on the Newton's second law of motion, the value of the net force acting on the object is equal to the product of the mass and the acceleration due to gravity. If we let a be the acceleration due to gravity, the equation that would allow us to calculate it's value is,
W = m x a
where W is weight, m is mass, and a is acceleration. Substituting the known values,
40 kg m/s² = (10 kg) x a
Calculating for the value of a from the equation will give us an answer equal to 4.
ANSWER: 4 m/s².
Answer:
I = 4.75 A
Explanation:
To find the current in the wire you use the following relation:
(1)
E: electric field E(t)=0.0004t2−0.0001t+0.0004
ρ: resistivity of the material = 2.75×10−8 ohm-meters
J: current density
The current density is also given by:
(2)
I: current
A: cross area of the wire = π(d/2)^2
d: diameter of the wire = 0.205 cm = 0.00205 m
You replace the equation (2) into the equation (1), and you solve for the current I:

Next, you replace for all variables:

hence, the current in the wire is 4.75A