Which real-world scenarios below represent physical changes?

Answer is: mixing water and powdered drink mix, combining oil and vinegar to make salad dressing, diluting bleach with water and dinner spreading peanut butter on bread.

Physical property can be observed and measured without any changes in molecular composition. The same substance is present before and after the psysical change, just with different form or state of matter. Making mixture is  physical change (physical change is reversible).

Running a car engine, exploding fireworks, taking aspirin for a headache and digesting Thanksgiving dinner are chemical change (chemical reaction), because new substances are formed, the atoms are rearranged and the reaction is followed by an energy change.