An electromagnet is created using a battery, an insulated copper wire, and an iron nail. the wire is wrapped around the nail 20 times and attached to the battery. which pair of changes will definitely increase the strength of the electromagnet?

Can you think of a way a rock unit with an older fossil could be above a rock until with a younger fossil? describe the scenario.

World class speed skaters can skate a 3,000-m course in about 4 minutes.what is their average speed for this course? a. 12.5 m/sb. 1.33 m/sc. 1.25 m/sd. 13.3 m/s

In a heat engine if 1000 j of heat enters the system the piston does 500 j of work, what is the final internal energy of the system if the initial energy was 2000 j? 1. write the equation 2.list out your known variables 3.plug the numbers into the equations 4.solve 5.write your solution statement that includes initial energy and final