Timmy and Sarah go for a hike. they hike 5 miles in three hours and 15 minutes. what is the average speed to the nearest 10th of a mile. (Hint - you need to convert minutes to hours)

The image shows the positions of a car on a roller coaster track. arrange the cars in order based on their gravitational potential energy. begin with the lowest potential energy and end with the highest.

What is the answer to these problems 30 pt

An electron and a proton are held on an x axis, with the electron at x = + 1.000 m and the proton at x = - 1.000 m. part a how much work is required to bring an additional electron from infinity to the origin? express your answer with the appropriate units. part b if, instead of the second electron coming in from infinity, it is initially at x = + 20.00 m on the axis and is given an initial velocity of 100.0 m/s toward the origin, does it reach the origin? part c how close to the origin does it come?