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:
5 weeks and 5 days is required to empty the lake
Explanation:
Officials begin the remove water from a full man made lake
The lake can be emptied in 4 weeks
= -1/4
A river can fill the lake up in 15 weeks
= 1/15
Let t represent the number of weeks that is required to empty the lake
= -1/t
Therefore the number of weeks it takes to empty the lake can be calculated as follows
-1/t= -1/4 + 1/15
-1/t= -11/60
Cross multiply
-11×t= -1×60
-11t= -60
t = 60/11
t= 5 5/11
Hence it takes 5 weeks and 5 days to empty the lake
The reasoning which is in use when large, angular rocks are interpreted to have originated from the outcrop at the top of the hill is; Fossil succession
<h3>Fossil succession of rocks</h3>
The principle of fossil succession in characterized by the fact that fossil entities succeed one another upward through rock layers in a definite and determinable order.
On this note, any time period can be dated by its fossil content.
Read more on fossil succession;
brainly.com/question/2631497
to be franc i really think the answer is B
