An elevator held by a single cable is ascending but slowing down. part a is the work done by tension positive, negative, or zero? is the work done by tension positive, negative, or zero? positive zero negative submitmy answersgive up part b what about the work done by gravity? what about the work done by gravity? positive zero negative

Refer to the diagram shown below.

By definition, 
Work  = Force * Distance

Part a.
The direction of motion is in the same direction as the tension in the cable. so the work done by tension is positive.

positive

Part b.
The direction of the weight (due to gravity) acts opposite to the direction of motion, so the work done by gravity is negative.

negative

You will hear a hissing sound because of the carbon dioxide escaping the can or bottle

The purpose of a lab is to do your "expirements" the importance of the topic is so you can now what the story is about and the last one is because no one is me with my question ( what is 3 over 4 x - 9 = 27 maybe you can )