C.
The train first sped up, giving it a positive acceleration in the beginning. This eliminates D since that choice states that it begins with a negative acceleration. This also eliminates B since that choice states that the train only had a negation acceleration.
Next, the train slows down, giving it a negative acceleration. We’re looking for the answer choice that starts with a positive acceleration and ends with a negative one. This makes C the correct answer. Hope this helps!
For help with this answer, we look to Newton's second law of motion:
Force = (mass) x (acceleration)
Since the question seems to focus on acceleration, let's get
'acceleration' all alone on one side of the equation, so we can
really see what's going on.
Here's the equation again:
Force = (mass) x (acceleration)
Divide each side by 'mass',
and we have: Acceleration = (force) / (mass) .
Now the answer jumps out at us: The rate of acceleration of an object
is determined by the object's mass and by the strength of the net force
acting on the object.
My very eager mother just served us nine pizzas
'Universe' means 'Everything'. That is, all matter, all space, all time.
