Question

On a straight road (taken to be in the +x direction) you drive for an hour at 50 km per hour, then quickly speed up to 90 km per hour and drive for an additional two hours.Required:a. How far do you go?b. What is your average x component of velocity?c. Why isn't vavg,x equal to the arithmetic average of your initial and final values of vx, (50+90)/2 = 70 km per hour?

Answer 1

Answer:

A.) 230 km

B.) 76.67 km/h

Explanation:

Given that On a straight road (taken to be in the +x direction) you drive for an hour at 50 km per hour, then quickly speed up to 90 km per hour and drive for an additional two hours.

A.) How far do you go?

When driving for an hour, the distance covered will be

Distance = speed × time

Distance = 50 × 1 = 50 km

When driving for additional 2 hours, the distance covered will be

Distance = 90 × 2 = 180 km

Total distance = 180 + 50 = 230 km

b. What is your average x component of velocity?

Average Velocity = total distance/ total time

Average velocity = 230/3

Average velocity = 76.67 km/h

c. Why isn't vavg,x equal to the arithmetic average of your initial and final values of vx, (50+90)/2 = 70 km per hour

They are not equal because of the displacement is the same as distance travelled.