Find the object's positions x1, x2, x3, and x4 at times t1=2.0s, t2=4.0s, t3=13s, and t4=17s.

The speed of the object is calculated while calculating the slope of the curve.

The speed of the object at t₁ = 2.0s is

The V₁ = slope at t₁

=7m-0m/3s-0s

= 2.33m/s

The speed of object t₂ = 40s is

The V₂ = slope at t₂

=7m-7m/6s-3s

= 0m/s

The speed of object t₃

= 13.0s is

V₃ = slope at t₃

= 7m-10m/16s-11s

= - 0.6m/s

The negative sign represents the direction

∴ The speed of object at time

t₃ = 13.0s is V₃ = 0.6m/s