Answer:
The unit that is a radical among the options is;
a. NH₄⁺
Explanation:
A radical is an atom, group of atoms molecule or ion that contains an electron that is unpaired. The presence of the unpaired electrons make radical very reactive as such most radicals enter into reactions with other species or with themselves to form new compounds making them not last long.
Radicals are also known as free radicals. Examples of radicals includes; Ammonium ion, NH₄⁺
Nitrate ion NO₃⁻ (From a salt)
Hydroxide ion OH⁻ (From a base)
Sulphate ion SO₄²⁺ (From an acid)
All of which are formed in aqueous solution of acids, salts and bases.
Complete Question
An athlete at the gym holds a 3.0 kg steel ball in his hand. His arm is 70 cm long and has a mass of 4.0 kg. Assume, a bit unrealistically, that the athlete's arm is uniform.
What is the magnitude of the torque about his shoulder if he holds his arm straight out to his side, parallel to the floor? Include the torque due to the steel ball, as well as the torque due to the arm's weight.
Answer:
The torque is 
Explanation:
From the question we are told that
The mass of the steel ball is 
The length of arm is 
The mass of the arm is 
Given that the arm of the athlete is uniform them the distance from the shoulder to the center of gravity of the arm is mathematically represented as

=>
=>
Generally the magnitude of torque about the athlete shoulder is mathematically represented as

=> 
=> 
As long as it sits on the shelf, its potential energy
relative to the floor is . . .
Potential energy = (mass) x (gravity) x (height) =
(3 kg) x (9.8 m/s²) x (0.8m) = <u>23.52 joules</u> .
If it falls from the shelf and lands on the floor, then it has exactly that
same amount of energy when it hits the floor, only now the 23.52 joules
has changed to kinetic energy.
Kinetic energy = (1/2) x (mass) x (speed)²
23.52 joules = (1/2) x (3 kg) x (speed)²
Divide each side by 1.5 kg : 23.52 m²/s² = speed²
Take the square root of each side: speed = √(23.52 m²/s²) = <em>4.85 m/s </em> (rounded)
Answer:
The ratio of T2 to T1 is 1.0
Explanation:
The gravitational force exerted on each sphere by the sun is inversely proporational to the square of the distance between the sun and each of the spheres.
Provided that the two spheres have the same radius r, the pressure of solar radiation too, is inversely proportional to the square of the distance of each sphere from the sun.
Let F₁ and F₂ = gravitational force of the sun on the first and second sphere respectively
P₁ and P₂ = Pressure of solar radiation on the first and second sphere respectively
M = mass of the Sun
m = mass of the spheres, equal masses.
For the first sphere that is distance R from the sun.
F₁ = (GmM/R²)
P₁ = (k/R²)
T₁ = (F₁/P₁) = (GmM/k)
For the second sphere that is at a distance 2R from the sun
F₂ = [GmM/(2R)²] = (GmM/4R²)
P₂ = [k/(2R)²] = (k/4R²)
T₂ = (F₂/P₂) = (GmM/k)
(T₁/T₂) = (GmM/k) ÷ (GmM/k) = 1.0
Hope this Helps!!!
The circumference of a circle is (2π · the circle's radius).
The length of a semi-circle is (1π · the circle's radius) =
(π · 14.8) = 46.5 (rounded)
(The unit is the same as whatever the unit of the 14.8 is.)