Question

the list below contains variables that can be manipulated in this investigation. select the three variables that the team investigated in order for them to determine each variables effect on the size of the magnetic force exerted by the electromagnet. 1
□ the number of turns of wire around the metal bar
□ the type of metal filings
□ the mass of metal filings lifted
□ the amount of current through the wire
□ the type of metal bar

Explanation:

To determine the variables investigated, we analyze the table (columns: Current through Electromagnet, Number of Turns of Coiled Wire, Type of Metal Bar, Mass of Iron Filings Lifted). The manipulated variables (independent) should be those changed to observe effect on magnetic force (via mass lifted, dependent).

• "the number of turns of wire around the metal bar": Column 2 (Number of Turns) varies, so manipulated.
• "the type of metal bar": Column 3 (Type: Iron, Nickel, Copper) varies, so manipulated.
• "the amount of current through the wire": Column 1 (Current) varies, so manipulated.

"the type of metal filings" is not a column (filings are iron, constant?); "the mass of metal filings lifted" is the dependent variable (measured, not manipulated).

Answer:

• the number of turns of wire around the metal bar
• the type of metal bar
• the amount of current through the wire