What action involves a chemical change?
making ice cubes, adding sugar to tea, cutting wrapping paper, baking a cake

BAKING A CAKE 

Chemical change is a process where a current substance changes or is made into a new type of substance. Unlike the physical change, which is reversible. Chemical change stays into a its new form. Take for instance these -physical change- examples, making ice cubes. The process involves solidification or freezing where the water becomes ice or solid but when it melts back to its original or typical form with respect to temperature, it’s still water. When the paper is cut into pieces it isn’t burned or exposed to a stimuli that can trigger immediate change in its composition. It’s still the same. On the contrary, baking a cake involves these different compositions or substances –flour, egg, yeast and etc. that is baked to a cake, a newly formed unified substance of all the included ingredients.      

Distance covered, s = 8ft - 4ft = 4 ftinitial velocity, u = 34 ft/sthe acrobat is moving upwards and therefore, a = -g = -9.81 m/s^2 = 32.19 ft/s^2applying equation of motion; s = ut -1/2gt^2then,4 = 34t -1/2*32.19t^24 = 34t - 16.095t^2rearranging; -16.095t^2 + 34t - 4 = 0solving the quadratic equation; t = {-34 +/- sqrt [34^2 - 4(-16.)]}/2(-16.095) = 1.06 +/- 0.93 = 0.13 or 1.99the acrobat will take 0.13 seconds to be at 8 ft above the ground. additionally, once at the maximum height, the acrobat will move down and be at the same spot (that is height) after 1.99 seconds moving down.

Answer is trees if this doesnt try using google