Maria and miquel were enjoying the fireworks when they got into a chemistry argument. maria insisted that the fireworks were the result of a chemical reaction. miguel disagreed. what would you tell them to solve this argument. a) it is a change of state, solid to gas, due to the addition of energy. b) it was a physical reaction since the fuse was lit and heat was produced. c) the color changes and the release of energy indicate a chemical reaction. d) it is an endothermic reaction because energy was added; therefore it is a chemical reaction,

The force acting on a beam was measured under the same operating conditions and a sample of 5 data points was collected. this process was repeated by 3 observers. the pooled standard deviations of these 3 data sets was 1.21. determine the true mean force using all pooled data (with a 95% probability). the result should look like this: true mean = mean +/- margin of error

In the middle of the night you are standing a horizontal distance of 14.0 m from the high fence that surrounds the estate of your rich uncle. the top of the fence is 5.00 m above the ground. you have taped an important message to a rock that you want to throw over the fence. the ground is level, and the width of the fence is small enough to be ignored. you throw the rock from a height of 1.60 m above the ground and at an angle of 54.0 degrees above the horizontal. part a part complete what minimum initial speed must the rock have as it leaves your hand to clear the top of the fence? express your answer with the appropriate units. part b for the initial velocity calculated in the previous part, what horizontal distance beyond the fence will the rock land on the ground?

How much heat is needed to raise the temperature of 5g of water by 16°c?