It’s my last question. what is the acceleration of the object in the graph?

-0.8 m/s²

Explanation:

All you need to do here is find the slope of that line. And since it's a line, it doesn't matter what two points you pick to do it; since the slope is the same throughout.

Slope = (y_2 - y_1)/(x_2 - x_1)

But in this case:

*Which is where the units for acceleration come from.

I chose the points (0,12) and (4,10) to get:

Acceleration = Slope = (4-12)/(10-0) = -8/10 = -0.8 m/s²

ice to water 1 water to vapour 2 latent heat

a lot of it means it can be "burned" for energy and sold at one price. if it is scarce, the price will go up