You drive your car from home at an average spped of 78km/h for 2 h. Halfway to your destination, you develop some engine problems, and for 4 h you nurse the car the rest of the way. What is your average velocity for the entire trip?
You spent six hours to take a trip of distance twice 78km/hr*2hrs
velocity= 2*78*2/6 km
check my thinking.
This is the answer that I got when I worked it, but the webassign homework that I have marked the answer incorrect. I thought that maybe I was doing something wrong or missing an important part of the problem, thus causing my answer to be wrong.
The answer would be 52 km/h.
That is the answer above. 2*2*78/6=52 km/hr
To calculate the average velocity for the entire trip, we need to determine the total displacement and the total time taken.
First, let's calculate the displacement during the first part of the trip. Since you drove for 2 hours at an average speed of 78 km/h, the distance covered can be calculated using the formula: distance = speed × time. Thus, the distance covered in the first 2 hours is (78 km/h) × (2 h) = 156 km.
Next, let's calculate the displacement during the second part of the trip. During the 4 hours while nursing the car, the distance covered is 0 km because you did not make any progress towards the destination.
Now, let's calculate the total time taken for the trip. The first part took 2 hours, and the second part took 4 hours, so the total time is 2 hours + 4 hours = 6 hours.
Finally, we can calculate the average velocity using the formula: average velocity = total displacement / total time.
Since the displacement during the first part is 156 km, the displacement during the second part is 0 km, and the total time is 6 hours, the average velocity for the entire trip is (156 km + 0 km) / 6 hours = 26 km/h.
Therefore, your average velocity for the entire trip is 26 km/h.