How do you describe and determine the direction of the magnetic field produced by an electric current?

When a 5.0kg cart undergoes a 2.2m/s increase in speed, what is the impulse of the cart

How is coal extracted from mountaintop removal mines? a. dynamite is used to create underground tunnels where miners go to extract the coal. b. dynamite is used to break apart rocks and then draglines are used to remove the broken rock and reach the coal. c. coal in mountaintops is extracted by digging strips in the landscape to reach the coal. d. placer deposits in mountain river bottoms are removed by

The ph is the a.independent variable b.the dependent variable c.control group