A train is moving in the positive direction down a track. First the train speeds up, and then it slows down. What is its acceleration? A. The train has positive acceleration throughout.
B. The train has negative acceleration throughout.
C. The train first has positive acceleration and then negative acceleration.
D. The train first has negative acceleration and then positive acceleration.

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!

the speed of the cart after 3 seconds of low fan speed is ⇒ 54.0 cm/s.

the speed of the cart after 5 seconds of medium fan speed is ⇒ 120.0 cm/s.

the speed of the cart after 2 seconds of high fan speed is ⇒ 64.0 cm/s. 

just did the lab.

Dshould be the right answer i think