They should identify the confounding variable.
Some condition that is not examined by the scientist might alter the experiment result. That condition is called confounding variable. If the method of the experiment same but result is very different, there should be unidentified confounding variable. It could be air humidity, temperature, ventilation, light, time of the year or anything that might not be seen by naked eye.
Try to redo the experiment with controlling variable as much as possible.
Sliding or rolling friction
The abbreviation Al, with one dot on top of the abbreviation, one on the left, one on the right.
Answer:
endothermic change occurs
Explanation:
photosynthesis, is an endothermic reaction in which energy is absorbed from the surrounding.
hope this helps