Stirring dry yeast into a bowl of hydrogen peroxide causes bubbles to form. blowing air into a glass of milk with a straw also causes bubbles to form. one of these is a physical change, and the other is a chemical change. how could you determine which type of change is occurring in each situation?

After a big snowfall, you take your favorite rocket-powered sled out to a wide field. the field is 195 m across, and you know that your sled accelerates at a rate of 3.65 m/s2 when the rocket is on. how much time will it take the sled to cross the field starting from rest, assuming the rocket is on the whole time?

Which of the following is the phase that results when the moon is on the opposite side of the earth from the sun? a. quarter moon b. crescent moon c. new moon d. full moon

What equation is used to calculate the weight of an object on a plant ?