Answer:
a) Vm = 72.5 km / h b) Vm = 72.5 km/h c) Vm = 0 km/h
Step-by-step explanation:
The measured speed of a body is the ratio of the total distance traveled between the time taken.
a) Here they tell us that it goes from San Antonio to Houston, half the time at 55 km/h and the other half at 90 km/h
Let's look for the distance traveled
V = x / t
X1 = V1 t / 2
X2 = V2 t / 2
The total distance the sum of the two distances
Xt = X1 + X2
Xt = V1 t / 2 + V2 t / 2
Xt = (V1 + V2) t / 2
Let's calculate the average speed
Vm = X / t
Vm = [(V1 + V2) t / 2] / t
Vm = (V1 + V2) / 2
Vm = (55 +90) / 2
Vm = 72.5 km / h
b) The return.
Following the same procedure as part a
Vm = (55+ 90) / 2
Vm = 72.5 km / h
c) go and return
The total distance to go and return is zero, since it returns to the starting point, which implies that the measured speed is zero
Vm = 0 km / h
d) Same as part c
e) See attachments, in this case we can add the vectors directly, since the positions are read in the graph
With the slope of the line you can calculate the speed,
To find the average speed we can draw a line from the starting point to the end, read the distance and divide by the time read