Question

a horse canters away from its trainer in a straight line, moving 150 m away in 13.0 s. it then turns abruptly and gallops halfway back in 4.7 s.
(a) calculate its average speed.

m/s
(b) calculate its average velocity for the entire trip, using \away from the trainer\ as the positive direction.

m/s

Explanation:

Step1: Calculate total distance

The horse moves \(150\) m away and then \(75\) m back. Total distance \(d = 150+75=225\) m.

Step2: Calculate total time

Total time \(t = 13.0 + 4.7=17.7\) s.

Step3: Calculate average speed

Average speed \(v_{avg - speed}=\frac{d}{t}=\frac{225}{17.7}\approx12.7\) m/s.

Step4: Calculate displacement

Displacement \(x=150 - 75 = 75\) m (since it moves \(150\) m away and \(75\) m back in the opposite direction).

Step5: Calculate average velocity

Average velocity \(v_{avg - velocity}=\frac{x}{t}=\frac{75}{17.7}\approx4.24\) m/s.

Answer:

(a) \(12.7\) m/s
(b) \(4.24\) m/s