Which of the following happens during conditions of eutrophication in a river?
a. oil spills lead to an excess of dissolved oxygen
b. fertilizers poison aquatic plants that require different nutrients from land plants
c. fertilizers from farm runoff chemically react with dissolved oxygen, making the water acidic and killing fish
d. nutrients from fertilizers cause thick mats of algae to grow, eventually leading to a
loss of dissolved oxygen

the first, second, and fifth options

d

explanation:

v=uf/(u-f)

= 5.10/(5-10) convex lens has positive focal length

=50/-5

=-10 cm (formed at other side)

cant without the picture! ?

the minimum constant speed at which she can catch the train is 2.7 m/s

given:

acceleration = 0.6

time = 4.5 s

to find:

velocity = ?

formula used:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

solution:

from 1st kinematic equation we get,

v = u + at

u = initial speed of train = 0 m/s

v = final speed of the train

a = acceleration of the train

t = time

v = 0 + (0.6 × 4.5)

v = 2.7 m/s

the minimum constant speed at which she can catch the train is 2.7 m/s