What is the average speed during acceleration?

In summary, the conversation discusses finding the average speed of a car that is initially moving at a constant speed of 13 m/s and then accelerates for 11 seconds with an acceleration of 1.4 m/s^2. The solution involves using the formula for distance and dividing it by the duration of the time interval.
  • #1
anglum
275
0

Homework Statement


A car is moving at a constant speed of 13 m/s
when the driver presses down on the gas pedal
and accelerates for 11 s with an acceleration
of 1:4 m/s2.
What is the average speed of the car during
the period? Answer in units of m=s.

The Attempt at a Solution



using the formula distance = Vi t + 1/2 A t squared
i solve for distance and then just simply divide that by the 11 seconds?
 
Last edited:
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  • #2
anglum said:

Homework Statement


A car is moving at a constant speed of 13 m/s
when the driver presses down on the gas pedal
and accelerates for 11 s with an acceleration
of 1:4 m/s2.
What is the average speed of the car during
the period? Answer in units of m=s.

The Attempt at a Solution



using the formula distance = Vi t + 1/2 A t squared
i solve for distance and then just simply divide that by the 11 seconds?

Note sure what you mean by 1:4 m/s^2 -- But your solution looks right
 
  • #3
No. Average speed is defined as [itex]\Delta d/\Delta t[/itex], where [itex]\Delta t[/itex] is the duration of the time span and [itex]\Delta d[/itex] is the distance traveled during this span. If you average the speeds at arbitrary time points over the time interval you will get a different (and incorrect) answer.

Edited to add:
As you divide the interval into ever small chunks, the average of the speeds does approach the average speed. It is far easier to calculate the average speed as defined.
 
Last edited:

1. What is average speed?

Average speed is the total distance traveled divided by the total time taken to travel that distance. It is a measure of how fast an object is moving on average.

2. How is average speed calculated?

To calculate average speed, divide the total distance traveled by the total time taken. This can be represented by the equation: average speed = total distance/total time.

3. What is the difference between average speed and instantaneous speed?

Average speed is the overall speed of an object over a given distance and time, while instantaneous speed is the speed at a specific moment in time. Average speed takes into account the entire journey, while instantaneous speed only looks at a single point in time.

4. Can average speed be greater than instantaneous speed?

Yes, it is possible for average speed to be greater than instantaneous speed. This can happen when an object moves at varying speeds throughout its journey. For example, if a car travels at 60 miles per hour for half of its journey and 80 miles per hour for the other half, its average speed would be greater than its instantaneous speed at any given moment.

5. How does average speed relate to velocity?

Velocity is a vector quantity that not only tells us the speed of an object, but also its direction. Average speed, on the other hand, is a scalar quantity that only tells us how fast an object is moving. Average speed and velocity are related in that they both involve measuring an object's displacement over time, but they are not the same thing.

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