A car accelerates from zero to 80 mph in 8.0 seconds. What is the average speed during this activity?
So I thought to calculate average speed it is S = distance/time
So 80/8 would be 10 m/s, but the answer is 40 MPH and I have no clue how :(
average of anything= sum/number of
average speed=(vi+vf)/2=80/2=40mph
To find the average speed, you need to first calculate the total distance traveled during the acceleration phase.
The formula to find distance traveled when the initial velocity is zero and acceleration is constant is given by:
distance = (1/2) * acceleration * (time^2)
In this case, the initial velocity is zero and the acceleration can be calculated using the formula:
acceleration = (final velocity - initial velocity) / time
Let's plug in the values:
Initial velocity = 0 mph
Final velocity = 80 mph
Time = 8 seconds
acceleration = (80 mph - 0 mph) / 8 seconds
acceleration = 10 mph/second
Now, let's find the distance traveled during this acceleration:
distance = (1/2) * 10 mph/second * (8 seconds)^2
distance = (1/2) * 10 mph/second * 64 seconds^2
distance = 320 mph * seconds
So, the car travels a distance of 320 mph * seconds during this acceleration phase.
To find the average speed, we divide the total distance by the total time taken:
average speed = total distance / total time
The total time taken is 8 seconds, as given in the question.
average speed = (320 mph * seconds) / 8 seconds
average speed = 40 mph
Therefore, the average speed during this acceleration is 40 mph.