he figure shows the motion diagram for a horse galloping in one direction along a straight path. Not every dot is labeled, but the dots are at equally spaced instants of time.

a) What is the horse’s velocity during the interval from 30 s to 40 s?

b) What is the horse’s velocity during the interval from 50 s to 70 s?

### 2 Answers

a) V = dx/dt = 50 m/10 s = 5 m/s

b) V = dx/dt = 200 m/20 s = 10 m/s

a)

Let t is time, S is the distance and V is the velocity of horse.

t1 = 30 seconds and t2 = 40 seconds…..

S1 = 300 meters and S2 = 350 meters

Use formula;

Velocity = ÎS / Ît

ÎS = S2 – S1 and Ît = t2 – t1

V = ÎS / Ît

V = ( S2 – S1 ) / ( t2 – t1 )

V = (350 – 300) / (40 – 30)

V = 50/10

V = 5 m/s

NOTE;; S2 will be greater than S1 and t2 will be greater than t1…

b.)

V = ÎS / Ît

V = (S2 – S1) / (t2 – t1)

V = (250 – 50) / (70 – 50)

V = 200 / 20

V = 10 m/s