Which best describes the purpose of a controlled experiment? A) to make sure the results of the experiment support the hypothesis
B) to prevent a dangerous condition resulting from a reaction
C) to examine whether one variable causes a change in another
B) to prevent an undesired change in a variable

An electromagnet is a device in which moving electric chargers in a coil of wire create a magnet.whats one advantage of using electromagnetic in devices

If an electric circuit is not grounded it is best to reach out and touch it to provide the ground a.true or b.false

The great sandini is a 60.0-kg circus performer who is shot from a cannon (actually a spring gun). you don’t find many men of his caliber, so you him design a new gun. this new gun has a very large spring with a very small mass and a force constant of 1100 n/m that he will compress with a force of 4400 n. the inside of the gun barrel is coated with teflon, so the average friction force will be only 40.0 n during the 4.00 m he moves in the barrel. at what speed will he emerge from the end of the barrel, 2.50 m above his initial rest position?