Rounded to the nearest whole number what is the atomic mass of platinum?

Which diagram correctly demonstrates the various forces acting on a ball moving horizontally with some speed?

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Students design a model roller-coaster track. they place a rubber ball at the highest point on the track and let it go. the ball rolls along the track pulled only by the force of gravity. eventually, it comes to a stop. which change to the design will result in the ball moving the greatest distance?