Distance And Motion Type Calculation Of A Car Accelerating From 10 M/s To 30 M/s

by Mei Lin 81 views

Hey guys! Let's dive into a classic physics problem that many of us encounter when learning about motion. We've got a car that starts with a speed of 10 m/s and accelerates to 30 m/s in just 4 seconds. The big questions we're tackling today are: how far did this car travel during this acceleration, and what kind of motion is it exhibiting? Buckle up, because we're about to explore the fascinating world of kinematics!

Unraveling the Distance Traveled

To figure out the distance the car covers, we first need to understand what's happening. Our car isn't just cruising at a constant speed; it's accelerating, meaning its speed is changing over time. This tells us we're dealing with uniformly accelerated motion, which is a key concept here. When dealing with this type of motion, we can't simply multiply the initial speed by the time to get the distance. We need to account for the change in speed.

There are a couple of ways we can approach this. One method is to use the average speed. Since the acceleration is uniform, the average speed is simply the average of the initial and final speeds. In our case, the initial speed (vi) is 10 m/s, and the final speed (vf) is 30 m/s. So, the average speed (v_avg) is calculated as:

v_avg = (vi + vf) / 2 = (10 m/s + 30 m/s) / 2 = 20 m/s

Now that we have the average speed, we can easily calculate the distance (d) traveled using the following formula:

d = v_avg * t

Where t is the time interval, which is 4 seconds in our problem. Plugging in the values, we get:

d = 20 m/s * 4 s = 80 meters

So, the car traveled 80 meters during those 4 seconds of acceleration. Pretty neat, right?

Another way to calculate the distance is by using one of the fundamental equations of motion for uniformly accelerated motion. This equation directly relates the distance traveled to the initial velocity, final velocity, acceleration, and time. The equation is:

d = vi * t + (1/2) * a * t^2

Where:

  • d is the distance traveled
  • vi is the initial velocity
  • t is the time
  • a is the acceleration

To use this equation, we first need to determine the acceleration (a) of the car. Acceleration is the rate of change of velocity, and it can be calculated as:

a = (vf - vi) / t = (30 m/s - 10 m/s) / 4 s = 5 m/s²

This means the car's velocity is increasing by 5 meters per second every second. Now we have all the pieces we need to plug into our equation for distance:

d = (10 m/s) * (4 s) + (1/2) * (5 m/s²) * (4 s)² d = 40 m + (2.5 m/s²) * (16 s²) d = 40 m + 40 m d = 80 meters

As you can see, we get the same result using both methods – the car traveled 80 meters. This consistency reinforces our understanding of uniformly accelerated motion and provides confidence in our calculations. It's always a good idea to double-check your work using different approaches, especially in physics!

Identifying the Type of Motion: Uniformly Accelerated Motion Explained

Now that we've calculated the distance, let's pinpoint the type of motion the car is experiencing. We've already touched on it, but let's formalize it: the car is undergoing uniformly accelerated motion (UAM), also known as constant acceleration. But what does that really mean?

Uniformly accelerated motion occurs when an object's velocity changes at a constant rate. In simpler terms, the object's speed is increasing (or decreasing) by the same amount every second. This constant rate of change in velocity is what we call acceleration. Our car fits this description perfectly – its velocity increases from 10 m/s to 30 m/s in 4 seconds, meaning it accelerates at a constant rate of 5 m/s². This consistency in the rate of velocity change is the hallmark of UAM.

To truly grasp uniformly accelerated motion, it's helpful to contrast it with other types of motion. For example, uniform motion (also known as constant velocity) is when an object moves at a constant speed in a straight line. There's no acceleration in uniform motion. Think of a car cruising down a highway at a steady 60 mph without changing its speed. On the other hand, non-uniformly accelerated motion occurs when the acceleration itself is changing. Imagine a car accelerating erratically, sometimes speeding up quickly, sometimes slowing down, and sometimes maintaining a constant speed. This type of motion is much more complex to analyze.

Uniformly accelerated motion is a fundamental concept in physics and has numerous real-world applications. We see it in action every day, from cars accelerating and braking to objects falling under the influence of gravity (neglecting air resistance). Understanding UAM allows us to predict and analyze the motion of objects in these scenarios. This is why it's such a crucial topic in introductory physics courses. The equations we used to solve for the distance traveled are specifically derived for UAM and wouldn't be applicable in cases of non-uniform acceleration.

Furthermore, the concept of uniformly accelerated motion forms the basis for understanding more complex motions, such as projectile motion (the motion of an object thrown into the air) and simple harmonic motion (the back-and-forth motion of a pendulum). By mastering the principles of UAM, you build a strong foundation for tackling more advanced topics in physics. So, understanding the consistent rate of change in velocity is key to understanding not just this problem, but a whole range of physical phenomena!

Why This Matters: The Relevance of Kinematics in Real Life

Now, you might be thinking, "Okay, this is interesting, but why do I need to know this?" Well, the principles of kinematics, which include understanding uniformly accelerated motion, are incredibly relevant in a variety of fields and everyday situations. It's not just about solving textbook problems; it's about understanding how the world around us works.

Think about engineering, for example. Engineers need to understand the motion of objects to design everything from cars and airplanes to roller coasters and robotic arms. When designing a car, engineers need to consider how quickly it can accelerate, how far it will travel while braking, and how its motion will be affected by different road conditions. These calculations all rely on the principles of kinematics, including the equations of motion we used earlier. Similarly, aerospace engineers use kinematics to design aircraft that can take off, fly, and land safely and efficiently. The principles of uniformly accelerated motion are fundamental to these designs.

In the realm of sports, kinematics plays a crucial role in analyzing athletic performance. Coaches and athletes use kinematic principles to optimize movements, improve technique, and prevent injuries. For instance, understanding the projectile motion of a baseball can help a batter improve their swing. By analyzing the launch angle, initial velocity, and trajectory of the ball, coaches can provide feedback to help batters hit with more power and accuracy. Similarly, kinematic analysis can help runners improve their stride length and frequency, leading to faster times. The application of these principles in sports highlights the practical benefits of understanding motion.

Even in forensic science, kinematics can be used to reconstruct accidents and determine the sequence of events. By analyzing skid marks, vehicle damage, and other evidence, investigators can use kinematic equations to estimate the speeds of vehicles involved in a collision and determine the cause of the accident. This application demonstrates the importance of kinematics in ensuring justice and safety.

On a more personal level, understanding kinematics can help you make better decisions in your daily life. For example, when driving, knowing the relationship between speed, braking distance, and reaction time can help you avoid accidents. Understanding how your car accelerates and decelerates allows you to anticipate traffic situations and react safely. Similarly, understanding the motion of objects can help you make better judgments when participating in sports or other physical activities.

Wrapping Up: Mastering Motion, One Problem at a Time

So, to recap, our car traveled 80 meters while accelerating from 10 m/s to 30 m/s in 4 seconds, and it exhibited uniformly accelerated motion. We tackled this problem using both the average speed method and the equations of motion, demonstrating the versatility of kinematic principles. We also explored the importance of understanding the type of motion involved, differentiating between uniform motion, uniformly accelerated motion, and non-uniformly accelerated motion.

Hopefully, this breakdown has not only helped you understand how to solve this specific problem but has also given you a broader appreciation for the principles of kinematics. Remember, physics isn't just about memorizing formulas; it's about understanding how the world works. By mastering these fundamental concepts, you'll be well-equipped to tackle more complex problems and gain a deeper understanding of the physical world around you. Keep practicing, keep exploring, and keep learning, guys! You've got this!