1. A 10 kg box is sliding along a smooth, frictionless surface at 3 m/s that also happens to be 2 m off the ground below. What is this box’s combined potential and kinetic energy (mechanical energy= Pe + Ke) 2. A ball is falling through the air straight down towards the ground below. The ball is 2.1 kg, is falling at 18 m/s, and happens to be 48 meters from the ground below. What is this box’s mechanical energy? (mechanical energy= Pe + Ke)

Abatter hits the baseball a with an initial velocity of v0 = 110 ft/sec directly toward fielder b at an angle of 23° to the horizontal; the initial position of the ball is 2.2 ft above ground level. fielder b requires 0.44 sec to judge where the ball should be caught and begins moving to that position with constant speed. because of great experience, fielder b chooses his running speed so that he arrives at the “catch position” simultaneously with the baseball. the catch position is the field location at which the ball altitude is 8.4 ft. determine the velocity of the ball relative to the fielder at the instant the catch is made.

If gases like carbon dioxide and methane make up less than 1% of the total atmosphere, why is it important for scientists to monitor changes in percentages of these gases?

Select all the correct answers. which two statements are true? a moving magnetic field creates an electric field. a constant magnetic field creates an electric field. a constant electric field creates a magnetic field. a moving electric field creates a magnetic field. resetnext