Pleasee answer asapp!! A train on a straight track goes in the positive direction for 6.7 km, and then backs up for 3.0 km. What is the distance covered by the train?

A. 3.7km
B. 0km
C. 6.7km
D. 9.7km

10 points! will mark brainiest! in a heat engine if 1,000 j of heat enters the system and the piston does 500 j of work, what is the final internal energy of the system if the initial energy was 2,000 j 1: write the equation 2: list out your known variables 3: plug the numbers into the equations 4: solve 5: write your solution statement that includes initial energy and final energy added you so much!