The height above the ground of a stone thrown upwards is given by s(t), where t is measured in seconds. After 1secondnothing, the height of the stone is 47feet above the ground, and after 1.5seconds, the height of the stone is 54feet above the ground. Evaluate s(1)and s(1.5),and then find the average velocity of the stone over the time interval [1,1.5].

v = 14 ft/s

Explanation:

By definition, the average velocity, is just the rate of change of the position, with respect to time, which can be written as follows:

       

Defining the vertical position as the y-coordinate, with the origin at ground level, and the upward direction as positive, we can write (1) as follows:

       

where yf = 54 ft, y₀ = 47 ft, tif = 1.5 s, t₀ = 1s.Replacing in (2) we get:

       

Letter a, because when there are unlike charges they will always attract to each other.