Aball was 2.0 m off the ground and thrown horizontally. it traveled for 7.8 m before it hit the ground. what was the imitial speed of the ball

12 m/s

Explanation:

First, find the time it takes for the ball to fall 2.0 m.

y = y₀ + v₀ t + ½ at²

0 = 2.0 + (0) t + ½ (-9.8) t²

0 = 2 − 4.9t²

t = 0.639

Find the velocity needed to travel 7.8 m in that time.

x = x₀ + v₀ t + ½ at²

7.8 = 0 + v₀ (0.639) + ½ (0) (0.639)²

7.8 = 0.639 v₀

v₀ = 12.2

Rounded to two significant figures, the initial velocity is 12 m/s.

trig 15.3 cos

  distance on the y-axis and time on the x-axis.

explanation:

the instantaneous velocity = change in position/time taken

the slope of the graph should give instantaneous velocity.

  slope of a graph = change in value of y -axis / change in values of x -axis

  comparing both the equations

    change in value of y -axis = change in position

  change in values of x -axis = time taken

so position values should be on the y axis and time values should be on the x axis.

distance on the y-axis and time on the x-axis.