Nancy wants to find out how the steepness of a hill's slope affects the amount of soil that erodes from it. she has soil, a long pan, and a pile of books with which to build a model hillside. she has a watering can to model rainfall. in her experiment, which of the following factors should nancy make sure that she does not change?

the amount of water she pours on the model

Explanation:

it is to be noted that an alpha particle is an helium nucleus. so it contains 2 protons 2 neutrons and has a mass number of 4. when alpha decay particles are ejected from the nucleus it gets transformed into an atom which has atomic number less than 2 and a mass number less than 4.

an equation that could represent alpha decay is radium 226 decay of alpha particle forms radon 222.

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for step 7 table c on the lab "newtons law of action"   the average time it took the car to travel .25 meters   was 1.92 seconds.

the average time it took the car to travel 0.50 meters was 2.61 seconds

hope this : )