Using the two kinematic equations that can be used for this problem are:
Vf = Vi + at and d=Vit +(1/2)*at^2
Since Vi (initial velocity) = 0
The equations can further be simplified where a is the acceleration, t is the time, Vf is the final velocity which is 70 miles per hour and d is 6 miles
Vf = at
70 = at
a = 70/t---equation 1
d=(1/2)*a*(t^2)
6 = (1/2)*a*(t^2) ---equation 2
Substituting equation 1 to equation 2.
6= (1/2)*(70/t)*(t^2)
6= 35t
t= 0.17142 hours or 10.28571 mins or 617.14 sec
Answer:
B. They are the electrons that interact with other atoms.
Explanation:
Valence electrons are the electrons in the outermost shell of an atom. These electrons are used by atoms to form bonds with other atoms during chemical bonding.
- So, the basis by which atoms interacts with one another is through the valence electrons.
- Without the valence electrons, atomic combination to form compounds would not be possible.
- Valence electrons are the most loosely held electrons and they have the lowest ionization energy.
Answer:The correct order is
γ-rays > x-rays> red light > infrared > radio
Explanation:
In the electromagnetic spectrum we have the following electromagnetic radiation Radio waves, infrared radiation, visible light, ultraviolet light, X-ray and gamma rays. Gamma rays have the highest frequency and radio waves the lowest. From the formula;
E=hf, where;
E is energy
h is Planck constant
f is frequency
We can see that the energy of these radiation depends on the magnitude of their frequency. Hence Gamma ray with highest frequency will have the highest energy and radio waves the lowest energy. Red light however is found at the lower end of the visible light spectrum . the correct order is;
γ-rays > x-rays> red light > infrared > radio
Answer:
a) The exit temperature is 430 K
b) The inlet and exit areas are 0.0096 m² and 0.051 m²
Explanation:
a) Given:
T₁ = 127°C = 400 K
At 400 K, h₁ = 400.98 kJ/kg (ideal gas properties table)
The energy equation is:
For a diffuser, w = Δp = 0
The diffuser is adiabatic, q = 0
Replacing:
Where
V₁ = 250 m/s
V₂ = 40 m/s
Replacing:
Using tables, at 431.43 kJ/kg the temperature is 430 K
b) The inlet area is:
The exit area is:
The number of protons determines the element. Many elements also have many isotopes. Such as carbon-14 Carbon-12 and carbon-10.
