Part C Find the height yi from which the rock was launched. Express your answer in meters to three significant figures. Learning Goal: To practice Problem-Solving Strategy 4.1 for projectile motion problems. A rock thrown with speed 12.0 m/s and launch angle 30.0 ∘ (above the horizontal) travels a horizontal distance of d = 19.0 m before hitting the ground. From what height was the rock thrown? Use the value g = 9.800 m/s2 for the free-fall acceleration. PROBLEM-SOLVING STRATEGY 4.1 Projectile motion problems MODEL: Is it reasonable to ignore air resistance? If so, use the projectile motion model. VISUALIZE: Establish a coordinate system with the x-axis horizontal and the y-axis vertical. Define symbols and identify what the problem is trying to find. For a launch at angle θ, the initial velocity components are vix=v0cosθ and viy=v0sinθ. SOLVE: The acceleration is known: ax=0 and ay=−g. Thus, the problem becomes one of two-dimensional kinematics. The kinematic equations are Horizontalxf=xi+vixΔtvfx=vix=constantVerticalyf=yi+viyΔt−12g(Δt)2vfy=viy−gΔt, Δt is the same for the horizontal and vertical components of the motion. Find Δtfrom one component, and then use that value for the other component. REVIEW: Check that your result has the correct units and significant figures, is reasonable, and answers the question. Model Start by making simplifying assumptions: Model the rock as a particle in free fall. You can ignore air resistance because the rock is a relatively heavy object moving relatively slowly.

University Physics Volume 1

18th Edition

ISBN:9781938168277

Author:William Moebs, Samuel J. Ling, Jeff Sanny

Publisher:William Moebs, Samuel J. Ling, Jeff Sanny

Chapter2: Vectors

Section: Chapter Questions

Problem 2.1CYU: Check Your Understanding Two motorboats named Alice and Bob are moving on a lake. Given the...

See similar textbooks

Learning Goal:

To practice Problem-Solving Strategy 4.1 for projectile motion problems.

A rock thrown with speed 12.0 m/s and launch angle 30.0 ∘ (above the horizontal) travels a horizontal distance of d = 19.0 m before hitting the ground. From what height was the rock thrown? Use the value g = 9.800 m/s2 for the free-fall acceleration.

PROBLEM-SOLVING STRATEGY 4.1 Projectile motion problems

MODEL: Is it reasonable to ignore air resistance? If so, use the projectile motion model.

VISUALIZE: Establish a coordinate system with the x-axis horizontal and the y-axis vertical. Define symbols and identify what the problem is trying to find. For a launch at angle θ, the initial velocity components are vix=v0cosθ and viy=v0sinθ.

SOLVE: The acceleration is known: ax=0 and ay=−g. Thus, the problem becomes one of two-dimensional kinematics. The kinematic equations are

Horizontalxf=xi+vixΔtvfx=vix=constantVerticalyf=yi+viyΔt−12g(Δt)2vfy=viy−gΔt,

Δt is the same for the horizontal and vertical components of the motion. Find Δtfrom one component, and then use that value for the other component.

REVIEW: Check that your result has the correct units and significant figures, is reasonable, and answers the question.

Model

Start by making simplifying assumptions: Model the rock as a particle in free fall. You can ignore air resistance because the rock is a relatively heavy object moving relatively slowly.

AI-Generated Solution

AI-generated content may present inaccurate or offensive content that does not represent bartleby’s views.