Answer:
The following statements are correct:
a) The car's average velocity on the final leg (from point B to A) of the trip is 1.39 m/s.
b) The car's average velocity for the entire trip is O m/s.
c) The car's average speed for the entire trip is 1.7 m/s.
Explanation:
a) We can calculate the car's average velocity of the final leg as:
v = d / t = 25 km / 5 h = 5 km/h = 5 . 1000 m / 3600 s = 1.39 m/s
where:
v: velocity in the final leg
d: displacement in the final leg
t: time of the travel from point B to point A
b) The car's average velocity for the entire trip is O m/s because the car is at same place at the end and at the beginning of the full travel.
v = d / t = 0 km / 8 h = 0 km/h = 0 . 1000 m / 3600 s = 0 m/s
where:
v: velocity in the entire travel
d: displacement in the entire travel
t: time of the entire travel
c) We can calculate the car's average speed for the entire trip as:
s = Δd / Δt = (d₁ + d₂) / (t₁ +t₂) = (25 km + 25 km) / (3h + 5h) = 50 km / 8h) = 6.25 km/h . 1000 m/km / 3600 s/h = 1.7 m/s
where:
s: speed in the entire travel
Δd = distance of the entire travel
Δt = time of the entire travel
d₁= distance of the first part of the travel (from A to B)
d₂= distance of the second part of the travel (from B to A)
t₁= time of the first part of the travel (from A to B)
t₂= time of the second part of the travel (from B to A)
