4. stairs are considered hazardous when a. the width of the treads does not strictly comply with codes. b. risers are less than 73/4 inches high. c. they're covered with carpeting. d. the height of the risers varies by more than 3/8 inch.

Renaldo and nasreen build an electromagnet by wrapping a wire around a nail and connecting the wire to both terminals of a battery. when they test the electromagnet, it can pick up 6 paper clips. their teacher wants all groups to pick up at least 10 paper clips. what could renaldo and nasreen do to increase the number of paper clips their electromagnet picks up?