Answer:
I = 0.483 kgm^2
Explanation:
To know what is the moment of inertia I of the boxer's forearm you use the following formula:
(1)
τ: torque exerted by the forearm
I: moment of inertia
α: angular acceleration = 125 rad/s^2
You calculate the torque by using the information about the force (1.95*10^3 N) and the lever arm (3.1 cm = 0.031m)

Next, you replace this value of τ in the equation (1) and solve for I:

hence, the moment of inertia of the forearm is 0.483 kgm^2
Answer:
T= 210.15 N
F= 75.31 N
Explanation:
Let the tension in string be T newton.
According to the question
⇒T×cos21°= mg
⇒T= mg/cos21°
⇒T=20×9.81/cos21
⇒T= 210.15 N
now, the magnitude of horizontal force
F= Tsin21°
⇒F= 210.15×sin21°
=75.31 N
................................
Answer:
R₁ = 0.126 m
Explanation:
Let's use the definition of intensity which is the power per unit area
I = P / A
the generated power is constant
P = I A
power is
P = E / t
if we perform the calculations for a given time, the wave energy is
E = q V
we substitute
P =
we can write this equation for two points, point 1 the antenna and point 2 the receiver
V₁A₁ = V₂A₂
A₁ =
A₁ = 0.1 10⁻³ 5 10⁻⁴ /V₁
A₁ = 5 10⁻⁸ /V₁
In general, the electric field on the antenna is very small on the order of micro volts, suppose V₁ = 1 10⁻⁶ V
let's calculate
A₁ = 5 10⁻⁸ / 1 10⁻⁶
A₁ = 5 10⁻² m²
the area of a circle is
A = π r²
we substitute
π R1₁²= 5 10⁻²
R₁ =
R₁ = 0.126 m
Answer:
1) 
2) 
3) 
4) The Molecules do not burn because of the presences of hydrogen bond in place
Explanation:
From the question we are told that
latent heat of vaporization for water at room temperature is 2430 J/g.
1)Generally in determining the molar mass of water evaporated we have that
-One mole (6.02 x 10. 23 molecules)
-Molar mass of water is 18.02 g/mol
Mathematically the mass of water is give as


Therefore


b)Generally the evaporation speed V is given as
Mathematically derived from the equation
To Give



c)Generally the equation for velocity 
Therefore
Effective temperature T is given by

where


4) The Molecules do not burn because of the presences of hydrogen bond in place