B: heat is transferred as thermal energy by the interaction of moving particles
Answer:
The value is 
Explanation:
From the question we are told that
The speed of each train is 
The speed of the bird is 
The distance between the trains is 
Generally the time taken before the collision occurs is mathematically represented as

=> 
=>
The total distance covered by the bird is mathematically represented as

=> 
=> 
Answer:
the net force is the same direction as the acceleration
Explanation:
so toward the center of the circle about which the object is constantly moving.
Its D because of the emission spectra
Answer:
a = R/2
Explanation:
Let R be the radius of the sphere and q = -2e be the charge in it. Let q₁ be the charge at radius a where the one of the point positive charges e is located. . Since the charge is uniformly distributed, the volume charge density is constant. So, q/4πR³ = q₁/4πa³
q₁ = q(a/R)³ = -2e(a/R)³. The electric force due to q₁ at r is F₁ = kq₁q/a² = kq²(a/R)³/a² = k(-2e)²a/R³ = 4ke²a/R³.
Let h be the distance between the two point charges. The electric force due to the one point charge on the other is F₂ = ke²/h²
If the net force on either charge is zero, then
F₁ = F₂
4ke²a/R³ = ke²/h²
a = R³/4h²
Since h = 2a, since the charges are equidistant from each other,
a = R³/4(2a)² = R³/8a²
a = R³/8a²
a³ = R³/8
a = ∛(R³/8)
a = R/2