Question

A car drives 10km with a speed of 72 km/hr and then runs out of gas. Then you walk 2km for the next 30 min until you find a gas station. (A) What is the displacement of the total trip? (B) How long does the entire trip take? (C) What is the average velocity of the entire trip?

Answer 1

Step-by-step explanation:

Answer:

(A) Total Displacement = 12 km

(B) t = 38.33 min

(C) Average Velocity = 18.8 km/h

Explanation:

(A)

The displacement of the trip is the sum of both distances:

Total Displacement = 10 km + 2 km

Total Displacement = 12 km

(B)

First we calculate the time taken by the car:

s = vt

where,

s = distance covered by car = 10 km

v = speed of car = 72 km/h

t = time taken = ?

Therefore,

t = (10 km)/(72 km/h)

t = (0.139 h)(60 min/1 h)

t = 8.33 min

now, we add the 40 min of walking in this:

t = 8.33 min + 30 min

t = 38.33 min

(C)

The average velocity is given as:

Average Velocity = Total Displacement/t = (12 km/38.33 min)(60 min/1 h)

Average Velocity = 18.8 km/h

Answer 2

(A) Total Displacement = 12 km

(B) t = 38.33 min

(C) Average Velocity = 18.8 km/h

Step-by-step explanation:

(A)

The displacement of the trip is the sum of both distances:

Total Displacement = 10 km + 2 km

Total Displacement = 12 km

(B)

First we calculate the time taken by the car:

s = vt

where,

s = distance covered by car = 10 km

v = speed of car = 72 km/h

t = time taken = ?

Therefore,

t = (10 km)/(72 km/h)

t = (0.139 h)(60 min/1 h)

t = 8.33 min

now, we add the 40 min of walking in this:

t = 8.33 min + 30 min

t = 38.33 min

(C)

The average velocity is given as:

Average Velocity = Total Displacement/t = (12 km/38.33 min)(60 min/1 h)

Average Velocity = 18.8 km/h