A ball rolls from x=-5 to x=32.4 m in 8.9 seconds. What was it’s average velocity

4.157 m/s

Explanation:

Average velocity: This can be defined as the ratio change in position to time interval. The S.I unit of average velocity is m/s

The expression for average velocity is given as,

V = Δx/t Equation 1

Where V = average velocity, Δx = change in position on the x- axis, t = time.

But,

Δx = x₂-x₁ Equation 2

Substitute equation 2 into equation 1

V = (x₂-x₁)/t Equation 3

Given: x₂ = 32.4 m, x₁ = -5 m, t = 8.9 s

Substitute into equation 3

V = [32.4-(-5)]/8.9

V = (32.4+5)/8.9

V = 37.4/8.9

V = 4.157 m/s

Hence the average velocity = 4.157 m/s

v = 4.20m/s

Average velocity is 4.20m/s

Explanation:

Average velocity is the change in displacement per unit time;

v = ∆x/t

Given;

∆x = 32.4 - (-5) = 37.4 m

t = 8.9 seconds

Substituting the values;

v = 37.4m/8.9s

v = 4.20m/s

Average velocity is 4.20m/s

d. air pressure decreases as altitude increases.