Answer:
a) m=20000Kg
b) v=0.214m/s
Explanation:
We will separate the problem in 3 parts, part A when there were no coals on the car, part B when there is 1 coal on the car and part C when there are 2 coals on the car. Inertia is the mass in this case.
For each part, and since the coals are thrown vertically, the horizontal linear momentum p=mv must be conserved, that is, 
, were each velocity refers to the one of the car (with the eventual coals on it) for each part, and each mass the mass of the car (with the eventual coals on it) also for each part. We will write the mass of the hopper car as 
, and the mass of the first and second coals as 
and 
respectively
We start with the transition between parts A and B, so we have:
Which means
And since we want the mass of the first coal thrown () we do:
Substituting values we obtain
For the transition between parts B and C, we can write:
Which means
Since we want the new final speed of the car (
) we do:
Substituting values we obtain
<span>"Does lack of sunlight affect plant growth?"
This question can be investigated with procedures according to
the Scientific Method, because "lack of sunlight" can be arranged
unambiguously, and "affected plant growth" can be identified
unambiguously.
The other questions involve words or phrases with ambiguous definitions,
that can mean different things to different people, and would be hard to
agree on, like "</span><span>best advice", "sound quality", and "happiness in life".</span>
Answer:
14 m/s²
Explanation:
Start with Newton's 2nd law: Fnet=ma, with F being force, m being mass, and a being acceleration. The applied forces on the left and right side of the block are equivalent, so they cancel out and are negligible. That way, you only have to worry about the y direction. Don't forget the force that gravity has the object. It appears to me that the object is falling, so there would be an additional force from going down from weight of the object. Weight is gravity (can be rounded to 10) x mass. Substitute 4N+weight in for Fnet and 1kg in for m.
(4N + 10 x 1kg)=(1kg)a
14/1=14, so the acceleration is 14 m/s²
Answer:
E
Explanation:
They will boil at the same temperature.
And remember Christ loves you and
Jesus is coming back soon get right with Christ please
Answer:
The statement is true: velocity and acceleration have opposite directions in the interval of braking.
Explanation:
Let's say we have a velocity 
.
The acceleration 
is the rate of change of the velocity 
. This means that if is <em>increasing during</em> time, then must be positive. But if is <em>decreasing over</em> time, then will be negative (even though the velocity is positive).
Mathematically:
decreases ⇒
⇒
.
Example:
