/*! 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 17 A ball is tossed from an upper-s... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

A ball is tossed from an upper-story window of a building. The ball is given an initial velocity of \(8.00 \mathrm{m} / \mathrm{s}\) at an angle of \(20.0^{\circ}\) below the horizontal. It strikes the ground \(3.00 \mathrm{s}\) later. (a) How far horizontally from the base of the building does the ball strike the ground? (b) Find the height from which the ball was thrown. (c) How long does it take the ball to reach a point \(10.0 \mathrm{m}\) below the level of launching?

Short Answer

Expert verified
The ball would strike the ground at a horizontal distance of 22.8 m from the base of the building. The height from which the ball was thrown is 20.7 m above the ground. The ball takes 1.43 s to reach a point 10.0 m below the level of launching.

Step by step solution

01

Calculate Horizontal Distance

First, let's calculate the horizontal component of the initial velocity using: \(v_{x_0} = v_{0} \cos(\theta)\). So, \(v_{x_0} = 8.00 m/s \cos(20.0^{\circ})\). We then use this to find the horizontal distance using: \(x = v_{x_0}t\). Where \(t=3.00s\) is the time it strikes the ground.
02

Calculate Initial Vertical Velocity

Next, we calculate the vertical component of the initial velocity using: \(v_{y_0} = - v_{0} \sin(\theta)\). Hence, \(v_{y_0} = - 8.00 m/s \sin(20.0^{\circ})\). The negative sign indicating the downward direction.
03

Find the Height

We use the equation: \(y = v_{y_0}t + \frac{1}{2}gt^{2}\) to calculate the height (y) where \(g = 9.8m/s^2\) is the acceleration due to gravity. The value for \(t\) is the time it takes to hit the ground, which is 3.00s.
04

Determine Time to Drop 10.0m

Finally, we determine the time it takes to drop 10.0m. We use the equation: \(t = \sqrt{(2y/g)}\), where \(y=10.0m\), the distance to drop from the initial level.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!

Key Concepts

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

Understanding Initial Velocity
When tackling a projectile motion problem, deciphering the initial velocity, denoted as \( v_0 \), is critical. It's essentially the speed at which the object is launched into the air, and it greatly influences the object's future trajectory. Breaking down \( v_0 \) into horizontal (\( v_{x_0} \)) and vertical (\( v_{y_0} \)) components unlocks the puzzle of the projectile's motion.

Imagine it like a sprinter (horizontal motion) battling against a strong wind (vertical motion). Now, in our exercise, we have a launch angle, showing the direction of the \( v_0 \), which was at a \(20.0^{\textcircled{a}}\) descent from the horizontal. Using trigonometry, we split this into \( v_{x_0} = v_0 \cos(\theta) \) for the horizontal sprint and \( v_{y_0} = -v_0 \sin(\theta) \) for the vertical gust, the minus sign indicating that the ball is thrown downwards. Understanding the initial velocities in both directions is pivotal as they affect how far and how fast the projectile will travel.
Calculating Horizontal Distance
Moving on to calculating the horizontal distance, think of it like measuring how far a frisbee has flown before touching the ground. In projectile motion, the horizontal distance, also known as range, depends on two things: the horizontal velocity (\( v_{x_0} \)) and the time the object spends airborne, \( t \).

Remember that in the absence of air resistance, the horizontal component of the velocity remains constant. So, we find the range by multiplying the horizontal velocity by the time of flight: \( x = v_{x_0}t \). In our exercise, we had already computed \( v_{x_0} \) and were given \( t = 3.00 \) seconds, giving us the clear trajectory distance from our building to the point of impact with the earth.
Determining Vertical Displacement
Vertical displacement, on the other hand, is akin to how deep a diver plunges into the ocean. It's the vertical distance the projectile has traveled from its starting point. Gravity plays an incessant game here, pulling our projectile downwards with acceleration \( g \), which is roughly \( 9.8 \) m/s² on Earth.

Essentially, we're looking at the equation \( y = v_{y_0}t + \frac{1}{2}gt^{2} \), which predicts the verticality of our adventure. Here, \( v_{y_0} \) is our initial vertical shove, \( t \) is our clock ticking away, and gravity? Gravity's role is depicted by the term \( \frac{1}{2}gt^{2} \), which factors in the constant acceleration towards the planet. We applied it all to find the height from which our spherical friend took the leap.
Acceleration Due to Gravity
Lastly, let's talk about the acceleration due to gravity, the force field that anchors us to the ground but also makes any projectile motion possible. Gravity is omnipresent, pulling objects toward the core of the Earth at \( 9.8 \) m/s², a value denoted by \( g \).

In the domain of projectile motion, gravity plays a dual role. It determines the time it takes objects to hit the ground after being launched (like our ball) or to reach a certain milestone, like the \( 10.0 \) m mark below the launch point. Gravity is a key player in equations like \( y = v_{y_0}t + \frac{1}{2}gt^{2} \) for vertical displacement or \( t = \sqrt{(2y/g)} \) to find the time to reach a given point. It's the universal force that ensures what goes up must come down, shaping the arch in projectile motion.

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

A Coast Guard cutter detects an unidentified ship at a distance of \(20.0 \mathrm{km}\) in the direction \(15.0^{\circ}\) east of north. The ship is traveling at \(26.0 \mathrm{km} / \mathrm{h}\) on a course at \(40.0^{\circ}\) east of north. The Coast Guard wishes to send a speedboat to intercept the vessel and investigate it. If the speedboat travels \(50.0 \mathrm{km} / \mathrm{h},\) in what direction should it head? Express the direction as a compass bearing with respect to due north.

A car is parked on a steep incline overlooking the ocean, where the incline makes an angle of \(37.0^{\circ}\) below the horizontal. The negligent driver leaves the car in neutral, and the parking brakes are defective. Starting from rest at \(t=0,\) the car rolls down the incline with a constant acceleration of \(4.00 \mathrm{m} / \mathrm{s}^{2},\) traveling \(50.0 \mathrm{m}\) to the edge of a vertical cliff. The cliff is \(30.0 \mathrm{m}\) above the ocean. Find (a) the speed of the car when it reaches the edge of the cliff and the time at which it arrives there, (b) the velocity of the car when it lands in the ocean, (c) the total time interval that the car is in motion, and (d) the position of the car when it lands in the ocean, relative to the base of the cliff.

An astronaut on a strange planet finds that she can jump a maximum horizontal distance of \(15.0 \mathrm{m}\) if her initial speed is \(3.00 \mathrm{m} / \mathrm{s} .\) What is the free-fall acceleration on the planet?

Heather in her Corvette accelerates at the rate of \((3.00 \hat{\mathbf{i}}-2.00 \hat{\mathbf{j}}) \mathrm{m} / \mathrm{s}^{2},\) while Jill in her Jaguar accelerates at \((1.00 \hat{\mathbf{i}}+3.00 \hat{\mathbf{j}}) \mathrm{m} / \mathrm{s}^{2} .\) They both start from rest at the origin of an \(x y\) coordinate system. After \(5.00 \mathrm{s},\) (a) what is Heather's speed with respect to Jill, (b) how far apart are they, and (c) what is Heather's acceleration relative to Jill?

A boy can throw a ball a maximum horizontal distance of R on a level field. How far can he throw the same ball vertically upward? Assume that his muscles give the ball the same speed in each case.

See all solutions

Recommended explanations on Physics Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.