D = distance between th two trains at the start of the motion = 100 miles
V = speed of the faster train towards slower train = 60 mph
v = speed of the slower train towards faster train = 40 mph
t = time taken by the two trains to collide = ?
time taken by the two trains to collide is given as
t = D/(V + v)
t = 100/(60 + 40) = 1 h
v' = speed of the bird = 90 mph
d = distance traveled by the bird
distance traveled by the bird is given as
d = v' t
d = 90 x 1
d = 90 miles
Answer:
density is 
Mg/µL
Explanation:
given data
density of nuclear = 
kg/m³
1 ml = 1 cm³
to find out
density of nuclear matter in Mg/µL
solution
we know here
1 Mg = 1000 kg
so
1 m³ is equal to cm³
and here 1 cm³ is equal to 1 mL
so we can say 1 mL is equal to 10³ µL
so by these we can convert density
density = kg/m³
density = kg/m³ × 
Mg/µL
density = Mg/µL
Explanation:
They will repel, meaning that they are made of an electrical conductor.
It is a comet that was a comet
Edit: You do mean Ridge?
Rocks near Mid-Ocean Ridge are younger than rocks near the trenches.
Seismic data shows oceanic crust is sinking into the mantle at the trenches.
Matching bands of magnetic rock are found on either side of the Ridge. Earth's magnetic fields change these bands over time.
