Ms. sullivan's class is investigating simple machines. today they are using a crowbar to lift a heavy desk. most students can lift the desk with the crowbar, even though they couldn't lift it with their bare hands.

one student in the class can't lift the desk even with the crowbar. what change should be made so the student can lift the desk?

a) use a crowbar that is longer than the first.
b) use a crowbar that is shorter than the first.
c) use a crowbar that is heavier than the first.
d) use a different type of lever that is the same length as the original crowbar.
eliminate

Hello there! :)

Ms. Sullivan's class is investigating simple machines. Today they are using a crowbar to lift a heavy desk. Most students can lift the desk with the crowbar, even though they couldn't lift it with their bare hands. 

One student in the class can't lift the desk even with the crowbar. What change should be made so the student can lift the desk?

Use a crowbar that is longer than the first is the correct answer. A crowbar is an example of a lever, a type of simple machine. The longer a lever is, the more you will be able to lift.

Therefore answer would be, A
Use a crowbar that is longer than the first.

The independent variable would be the fertilizer as it is what the dependent variable (the growth of grass) depends on.