Finding constant acceleration, unit difficulty

In summary, the equation for calculating acceleration is final velocity = initial velocity + (acceleration x time). Using this equation and the given values of 4m/s for initial velocity, 36m/s for final velocity, and 4 seconds for time, the acceleration of the Indy 500 race car can be calculated to be 8m/s^2. It is important to note that when dividing units, both time units must be in the denominator, so the correct units for acceleration are meters per second squared (m/s^2).
  • #1
PhysicallyAbel
26
1

Homework Statement


An Indy 500 race car's velocity increases from 4m/s to 36m/s over a 4 second time interval. What is its acceleration? 4m/s is the initial velocity, 36 m/s is the final velocity, and time is 4 seconds.

Homework Equations


final velocity = initial velocity + (acceleration x time)[/B]

The Attempt at a Solution


36m/s = 4m/s + a(4s)
32m/s = a(4s)
a = 8?[/B]

Here's my problem. I know how to work out the equation and solve for acceleration. However, when you divide 32m/s by 4 seconds, I thought that you canceled the units. Which means you would be left with 8 meters (because seconds cancel out). However, I'm aware the correct answer is 8m/s^2 because acceleration is always squared.

Can someone explain my fundamental misunderstanding? It's so simple, but It's really confusing me.
 
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  • #2
You cannot cancel the units, both time units are in the denominator:

1 m/s / (1 s) = 1 ((m/s)/s) = 1 m/s^2

just as (1/2)/2 = 1/4 and not (1/2)/2 = 1.
 
  • #3
Orodruin said:
You cannot cancel the units, both time units are in the denominator:

1 m/s / (1 s) = 1 ((m/s)/s) = 1 m/s^2

just as (1/2)/2 = 1/4 and not (1/2)/2 = 1.

Thank you so much, I knew I was making an elementary mistake. I'm an idiot.
 

What is constant acceleration?

Constant acceleration is the rate of change of velocity over time, where the velocity increases or decreases by the same amount every second.

How is constant acceleration calculated?

Constant acceleration can be calculated by dividing the change in velocity by the change in time. This can be represented by the equation a = (vf - vi) / t, where a is acceleration, vf is final velocity, vi is initial velocity, and t is time.

What are some units used to measure acceleration?

Acceleration can be measured in units such as meters per second squared (m/s^2) or feet per second squared (ft/s^2).

Why is constant acceleration important?

Constant acceleration is important because it allows us to understand and predict the motion of objects. It is also a fundamental concept in physics and is used in many real-world applications such as engineering and space travel.

What are some real-life examples of constant acceleration?

Examples of constant acceleration in everyday life include a car accelerating from a stop, a roller coaster going down a hill, and a basketball being thrown into the air. In each of these cases, the velocity increases or decreases by the same amount every second, resulting in constant acceleration.

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