The amount of oxygen in the reactants is 4 atoms. in the products, the oxygen is distributed to water (h20) and o2 gas.
which coefficients would be placed in front of water and oxygen?
2 in front of water and 2 in front of oxygen
1 in front of water and 2 in front of oxygen
1 in front of water and 1 in front of oxygen
2 in front of water and 1 in front of oxygen

3 1/4

Explanation:

cause the 1 in front is bigger then the 2 in the back

2 in front of water and 1 in front of oxygen

Explanation:

There are 4 oxygen atoms in the reactants, so there will be 4 oxygen atoms in the products.

If you have 2 O₂ molecules, there won't be any oxygen atoms left for H₂O molecules.  So there must be a 1 coefficient in front of the O₂ product.

If there's 1 O₂, that leaves 2 oxygen atoms for water.  So there must be a 2 coefficient in front of the H₂O.

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

im srry but ur wrong the answer is d a smooth rock, some red dirt, and an empty bird's nest.