/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 31 A fast pitch. The fastest measur... [FREE SOLUTION] | 91Ó°ÊÓ

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A fast pitch. The fastest measured pitched baseball left the pitcher's hand at a speed of 45.0 \(\mathrm{m} / \mathrm{s}\) . If the pitcher was in contact with the ball over a distance of 1.50 \(\mathrm{m}\) and produced constant acceleration, (a) what acceleration did he give the ball, and (b) how much time did it take him to pitch it?

Short Answer

Expert verified
(a) Acceleration is 675 m/s². (b) Time is 0.0667 s.

Step by step solution

01

Identify known values

Identify the known values from the problem description. The initial velocity ( $v_i$) is 0 m/s (since the ball starts from rest), final velocity ( $v_f$) is 45.0 m/s, and the distance ( $s$) is 1.50 m.
02

Apply kinematic equation for acceleration

Use the kinematic equation \(v_f^2 = v_i^2 + 2a s\) to solve for the acceleration (\(a\)). \ Substitute the known values: \ \((45.0 \, \mathrm{m/s})^2 = (0 \, \mathrm{m/s})^2 + 2a(1.50 \, \mathrm{m})\). \ This simplifies to: \[ 2025 = 3a \] \ Solve for \( a \): \[ a = \frac{2025}{3} = 675 \, \mathrm{m/s^2} \]
03

Apply kinematic equation for time

Now that we have the acceleration, use the kinematic equation \(v_f = v_i + at\) to find the time (\(t\)).\ We know \(v_i = 0 \, \mathrm{m/s}\), \ \(v_f = 45.0 \, \mathrm{m/s}\), \ and \(a = 675 \, \mathrm{m/s^2}\), so substitute these values into the equation: \ \(45.0 = 0 + 675 \, t\). \ Solve for \( t \): \ \(t = \frac{45.0}{675} = 0.0667 \, \mathrm{s}\).

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Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Constant Acceleration
In physics, constant acceleration means that an object's velocity is changing at a uniform rate. This implies that for each unit of time, the object's velocity increases or decreases by the same amount. In the context of the exercise, the pitcher exerts a steady force on the baseball that results in the ball gaining speed at a constant rate over the distance it is in contact with the pitcher's hand. This means that no matter how much time passes during the pitch, the acceleration remains the same until the ball is released.
  • A constant acceleration ensures that calculations using kinematic equations remain straightforward.
  • It's essential to remember that in real-life scenarios, many factors can cause the acceleration to vary, such as air resistance or changes in force.
Understanding constant acceleration helps simplify many physics problems since only simple algebraic solutions are needed.
Initial and Final Velocity
Velocity is critical in understanding motion. In this problem, we focus on the ball's initial and final velocities:
The **initial velocity** is the velocity of the baseball when the movement starts, which is given as 0 m/s since the ball is initially at rest.
The **final velocity** is the speed the ball reaches just before leaving the pitcher's hand, which is given as 45.0 m/s. Knowing these values is crucial for applying kinematic equations. These equations allow us to find other critical parameters like acceleration or distance traveled. Here, these velocities help us determine how the ball's speed increases due to constant acceleration:
  • Initial velocity (\( v_i \)) can often be zero, simplifying calculations.
  • Final velocity (\( v_f \)) indicates how fast the object moves at the end.
The difference between these velocities gives insight into how much an object speeds up during the motion.
Distance Traveled
Distance traveled is a straightforward but essential component in many kinematic problems. In this problem, it's the length over which the pitcher and the baseball are in contact, which is 1.50 meters. This distance plays a significant role in calculating the constant acceleration:
  • It affects the kinematic equation (\(v_f^2 = v_i^2 + 2as\)) by determining the acceleration required to achieve the desired velocity.
  • A longer distance would lead to a lesser acceleration for a given final velocity, whereas a shorter distance would require a greater acceleration.
Knowing the exact distance helps us apply the right mathematical model to find solutions accurately. Such insights are vital when designing systems involving motion, ensuring that components can handle necessary forces.
Acceleration Calculation
Calculating acceleration is about determining how quickly an object changes its velocity. In this exercise, we used one of the key kinematic equations:\[ v_f^2 = v_i^2 + 2as \]By substituting the known values:
  • \(v_i = 0 \) (initial velocity = 0 m/s)
  • \(v_f = 45.0 \) (final velocity = 45.0 m/s)
  • \(s = 1.50 \) (distance = 1.50 m)
We solve for \(a\) (acceleration), finding it to be 675 m/s². This is a straightforward substitution problem:\[ 45^2 = 0 + 2 imes a imes 1.50 \] Leads to a simplification: \[ 2025 = 3a \] So, the acceleration \( a = 675 \, \mathrm{m/s^2} \).This calculation is essential in physics, often used in designing transportation or understanding dynamics, ensuring safety measures where extreme accelerations could be harmful.

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Most popular questions from this chapter

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