Answer:
The speed decreases.
Explanation:
This can be explained using the conservation of linear momentum.
Since there is no friction, the initial moment of the train must be equal to its linear moment after it is filled with water.
the initial linear momentum is

where
is the initial mass of the train, and
the initial speed of the train.
And linear momentum after the water filled the train car is

where
is mass of the train after the rain, and
the speed of the train after the rain
<u>the equality must be fulfilled:</u>

We know that if water is added to the train,
that is the mass after the water is added, is greater than
which is the mass of the train without the water.
Therefore, in order for the conservation of the linear momentum to be fulfilled: 
the speed after the water is added (
) must be smaller than the initial train speed (
) . So the speed of the car decreases.
Answer:
The average acceleration of the ball during the collision with the wall is 
Explanation:
<u>Known Data</u>
We will asume initial speed has a negative direction,
, final speed has a positive direction,
,
and mass
.
<u>Initial momentum</u>

<u>final momentum</u>

<u>Impulse</u>

<u>Average Force</u>

<u>Average acceleration</u>
, so
.
Therefore, 
The answer is number 2 stomata.
<h3><u>Answer;</u></h3>
<em>Electric motor</em>
<h3><u>Explanation;</u></h3>
- <em><u>Energy</u></em> is the ability to do work. According to the law of conservation of energy,<em><u> energy can not be created nor destroyed but can be changed from one form to another</u></em>.
- Changing energy from one form to another is done by devices we call <em><u>transducers. These are elements that convert energy from one form to another.</u></em>
- In this case, electrical motor is an example of a transducer that converts electrical energy to kinetic energy. <em><u>Electrical energy is supplied to a the motor which converts it to rotational energy or mechanical energy then to kinetic energy.</u></em>