Teen Hoodlum in his souped-up jalopy is traveling along a deep dip in the road. Suppose Hoodlum weighs 170 lb (as measured when standing at rest on a spring scale). When he passes through the lowest point of the circular-shaped dip, with an effective radius of 50 m, the seat must exert an upward supporting force of 250 lb on him. What is his speed at that point

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

Sawyer is studying diffraction. he draws a diagram of a plane wave to show how light waves travel. which best describes sawyer’s error? the wave fronts should be perpendicular to the direction in which the waves move. the arrow showing the direction of movement of the waves should be pointing to the left. the arrow showing the direction of movement of the waves should be pointing downward. the wave fronts should be both parallel and perpendicular to the direction in which the waves move.

If an athlete runs once around a track, back to the starting line, her average velocity is zero. true or false?