/*! 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 74 In a stunt being filmed for a mo... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

In a stunt being filmed for a movie, a sports car overtakes a truck towing a ramp, drives up and off the ramp, soars into the air, and then lands on top of a flat trailer being towed by a second truck. The tops of the ramp and the flat trailer are the same height above the road, and the ramp is inclined 16 above the horizontal. Both trucks are driving at a constant speed of 11 m/s, and the flat trailer is 15 m from the end of the ramp. Neglect air resistance, and assume that the ramp changes the direction, but not the magnitude, of the car’s initial velocity. What is the minimum speed the car must have, relative to the road, as it starts up the ramp?

Short Answer

Expert verified
The minimum speed the car must have is approximately 11.45 m/s.

Step by step solution

01

Analyze the Problem

The problem involves a car launching off a ramp inclined at 16° and landing on a trailer that is 15 meters away. We need to find the car's initial speed as it goes off the ramp to cover this distance.
02

Break Down the Motion Components

Separate the car's motion into horizontal and vertical components. The initial speed needs to be split into these components using the angle of inclination.
03

Horizontal Motion Analysis

Since there is no acceleration horizontally, the horizontal component of the velocity, \( v_{x} \), is constant. Use the horizontal distance and the time of flight to express \( v_{x} \): \( v_{x} = v \cos(16^{\circ}) \).
04

Vertical Motion Analysis

The vertical component of the initial velocity, \( v_{y} \), is used to determine flight time. The vertical motion can be expressed as \( v_{y} = v \sin(16^{\circ}) \). The car must land at the same vertical level it started from, implying symmetry in flight time up and down.
05

Calculate the Time of Flight

For horizontal motion, \( d = v_{x} \cdot t \). Using the given distance of 15 m: \( 15 = 11 \cos(16^{\circ}) \cdot t \). Solve this for \( t \).
06

Find the Initial Speed

Since horizontal speed is constant at the speed of the truck, \( v_{x} = 11 \text{ m/s}\). Substitute \( v \cos(16^{\circ}) = 11 \) to find \( v \).

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.

Inclined Plane
An inclined plane is simply a flat supporting surface tilted at a certain angle, relative to a horizontal surface. In this exercise, the car drives up a ramp inclined at 16 degrees. The ramp, acting as an inclined plane, changes the direction of the car's velocity without altering its magnitude. Understanding how inclined planes work is crucial when analyzing projectile motion because they determine how objects are launched into the air.

When an object moves up an inclined plane, gravity affects its velocity differently than if it were moving on horizontal ground. The angle of incline affects how the object's velocity is split into horizontal and vertical components. We'll see how these components come into play as we look at the initial velocity and its components in the next sections.
Initial Velocity
The car's initial velocity is fundamental in determining how far it will travel after launching off the ramp. This is the speed at which the car leaves the ramp, and the magnitude remains constant despite the change in direction initiated by the inclined plane.

To find the initial velocity required for the car to land on the target, it's split into two components: horizontal and vertical. This analysis allows us to use trigonometric functions to determine these components based on the angle of the ramp. The goal is to calculate the minimum initial velocity that ensures the car covers the required distance of 15 meters while maintaining the same vertical height.
Horizontal and Vertical Components
Projectile motion involves both horizontal and vertical movements. The initial velocity needs to be separated into these two components. In the problem, we assume that the ramp changes only the direction, not the magnitude, of the car's speed. This means:

  • The horizontal component, \( v_{x} \), is calculated as \( v \cos(16^{\circ}) \). It remains constant due to zero horizontal acceleration.
  • The vertical component, \( v_{y} \), is given by \( v \sin(16^{\circ}) \).


These equations allow us to express horizontal and vertical movements in terms of the initial speed and the angle of inclination. Knowing these components lets us further solve for the time of flight and ensure the car lands correctly on the trailer.
Time of Flight
The time of flight is the total time the car spends in the air after leaving the ramp. This is crucial for predicting if it will land accurately on the target. In this context, since the horizontal speed remains constant and the car lands at the same height it was launched from, there is symmetry in the time taken to ascend and descend.

We use the horizontal component of movement to determine the time of flight. The relationship between the horizontal distance (15 m), horizontal speed, and time can be expressed as:
\[ 15 = 11 \cos(16^{\circ}) \cdot t \]
Solving this equation provides the time the car is airborne. With this information, we can further ensure that the calculated time of flight leads to successful landing on the trailer.

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

Two friends, Barbara and Neil, are out rollerblading. With respect to the ground, Barbara is skating due south at a speed of 4.0 m/s. Neil is in front of her. With respect to the ground, Neil is skating due west at a speed of 3.2 m/s. Find Neil’s velocity (magnitude and direction rel- ative to due west), as seen by Barbara.

As a tennis ball is struck, it departs from the racket horizontally with a speed of 28.0 m/s. The ball hits the court at a horizontal distance of 19.6 m from the racket. How far above the court is the tennis ball when it leaves the racket?

Stones are thrown horizontally with the same velocity from the tops of two different buildings. One stone lands twice as far from the base of the building from which it was thrown as does the other stone. Find the ratio of the height of the taller building to the height of the shorter building.

A space vehicle is coasting at a constant velocity of 21.0 m/s in the y direction relative to a space station. The pilot of the vehicle fires a RCS (reaction control system) thruster, which causes it to accelerate at 0.320 \({m} / {s}^{2}\) in the x direction. After 45.0 s, the pilot shuts off the RCS thruster. After the RCS thruster is turned off, find (a) the magnitude and (b) the direction of the vehicle’s velocity relative to the space station. Express the direction as an angle measured from the y direction.

On a pleasure cruise a boat is traveling relative to the water at a speed of 5.0 m/s due south. Relative to the boat, a passenger walks toward the back of the boat at a speed of 1.5 m/s. (a) What are the magnitude and direction of the passenger’s velocity relative to the water? (b) How long does it take for the passenger to walk a distance of 27 m on the boat? (c) How long does it take for the passenger to cover a distance of 27 m on the water?

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.