You have trained all year for a marathon. in your first attempt to run a marathon, you decide that you want to complete this 26-mile race in 4.5 hours.
what would your average speed have to be to complete the race in 4.5 hours? give you answer in kilometers per hour.

Two charged particles, q1 and q2, are located on the x-axis, with q1 at the origin and q2 initially at x1 = 12.2 mm. in this configuration, q1 exerts a repulsive force of 2.62 µn on q2. particle q2 is then moved to x2 = 18.0 mm. what is the force (magnitude and direction) that q2 exerts on q1 at this new location? (give the magnitude in µn.)