A<span> barometer is used to measure air pressure. </span>
Answer: One of the signs a chemical reaction is taking place is the presence of bubbles. :)
A control is something you don't touch/change in a exprement, a constant is the same as the control, the independent is the one the you do vhange, the dependet is the one that you observe/ use your 5 sences with.
The power require to keep the car traveling is 6,666 W.
The power of the engine at the given efficiency is 3,999.6 W.
<h3>What is Instantaneous power?</h3>
This the product of force and velocity of the given object.
The power require to keep the car traveling is calculated as follows;
P = Fv

The power of the engine at the given efficiency is calculated as follows;

Learn more about efficiency here: brainly.com/question/15418098