/*! 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 Genesis Crash. On September \(8,... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

Genesis Crash. On September \(8,2004\) , the Genesis space-craft crashed in the Utah desert because its parachute did not open. The \(210-k g\) capsule hit the ground at 311 \(\mathrm{km} / \mathrm{h}\) and penetrated the soil to a depth of 81.0 \(\mathrm{cm} .\) (a) Assuming it to be constant, what was its acceleration \(\left(\text { in } \mathrm{m} / \mathrm{s}^{2} \text { and in } g^{\prime} \mathrm{s}\right)\) during the crash? (b) What force did the ground exert on the capsule during the crash? Express the force in newtons and as a multiple of the capsule's weight. (c) For how long did this force last?

Short Answer

Expert verified
(a) The acceleration was \(-4606.8 \, \text{m/s}^2\) or \(-469.6 \, g\). (b) The force was \(967428 \, \text{N}\) or \(469.6\) times the capsule's weight. (c) The force lasted for \(0.0187 \, \text{s}\).

Step by step solution

01

Convert Speed to Meters per Second

First, convert the initial velocity from km/h to m/s. Given: \( v_i = 311 \, \text{km/h} \). To convert to \( \text{m/s} \), use the conversion factor: 1 km/h = 0.27778 m/s. \[ v_i = 311 \, \text{km/h} \times 0.27778 \, \text{m/s per km/h} = 86.39 \, \text{m/s} \]
02

Define Final Velocity and Distance

Since the capsule comes to a complete stop, the final velocity \( v_f = 0 \, \text{m/s} \). The penetration depth into the soil is given as \( 81 \, \text{cm} \), which must be converted to meters for SI unit consistency: \[ \text{Distance} \, d = 0.81 \, \text{m} \]
03

Calculate Deceleration Using Kinematic Equation

Use the kinematic equation to find acceleration \( a \): \[ v_f^2 = v_i^2 + 2a \,d \]Substitute in the known values: \[ 0 = (86.39)^2 + 2a \times 0.81 \] Solve for \( a \):\[ a = \frac{- (86.39)^2}{2 \times 0.81} = -4606.8 \, \text{m/s}^2 \]
04

Convert Acceleration to g's

Acceleration in terms of \( g \), where \( g = 9.81 \, \text{m/s}^2 \):\[ a = -\frac{4606.8}{9.81} \, g \] \[ a \approx -469.6 \, g \]
05

Calculate Force Exerted on Capsule

Use Newton's second law, \( F = ma \), to find the force.Given mass \( m = 210 \, \text{kg} \), acceleration \( a = -4606.8 \, \text{m/s}^2 \):\[ F = 210 \times (-4606.8) = -967428 \, \text{N} \] The force exerted by the ground is positive and equal in magnitude: \[ F = 967428 \, \text{N} \]
06

Calculate Force as a Multiple of Weight

First, find the weight of the capsule: \[ W = mg = 210 \times 9.81 = 2060.1 \, \text{N} \] Then, express the ground force as a multiple of the weight: \[ \text{Multiple of Weight} = \frac{967428}{2060.1} \approx 469.6 \]
07

Calculate the Duration of Forces

Using the change in velocity \( \Delta v = v_f - v_i = -86.39 \, \text{m/s} \) and acceleration \( a = -4606.8 \, \text{m/s}^2 \):Use the formula \( t = \frac{\Delta v}{a} \):\[ t = \frac{-86.39}{-4606.8} \approx 0.0187 \, \text{s} \]

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.

Kinematics
Kinematics is a branch of physics that deals with the motion of objects. It doesn't concern itself with the causes of motion, focusing instead on the geometry of motion. In our exercise, the kinematics concepts are crucial for understanding how the Genesis capsule, traveling at high speed, behaves upon impact with the ground.

To analyze such motion, we commonly use equations of motion to relate the different variables: initial velocity, final velocity, displacement, acceleration, and time. For instance, using the kinematic equation \[ v_f^2 = v_i^2 + 2a \,d \]one can determine the unknown acceleration when the other quantities are known.
  • Initial velocity \( v_i \): How fast the object is moving initially.
  • Final velocity \( v_f \): The velocity of the object at the end of the motion. In our problem, this is when the object stopped, hence \( v_f = 0 \).
  • Displacement \( d \): How far the object travels during its motion. Here, it's the penetration depth.
  • Acceleration \( a \): The rate at which velocity changes with time.
Newton's Laws of Motion
Newton's Laws of Motion help us understand how forces and motion interact. Specifically, the second law is applicable in our exercise, where it links the force exerted on an object with its mass and acceleration. The formula is given by:\[ F = ma \]

In our problem, the ground exerts a force on the Genesis capsule following a sudden stop after high-speed impact. This law tells us that the force is directly proportional to the mass of the object and its acceleration or deceleration.

A few key insights from this:
  • If the acceleration increases, so does the force, assuming mass remains constant.
  • The force calculated is said to be equal and opposite to that applied by the capsule to the Earth's surface, reflecting Newton's third law.
  • Since deceleration is negative acceleration indicating a reduction in velocity, the force calculated using this value reflects a sizable impact due to the high value of deceleration.
Acceleration and Gravity
Understanding the concepts of acceleration and gravity is fundamental, particularly in high-speed impacts, like with the Genesis capsule.

Acceleration is a measure of the change in velocity over time. When calculating the deceleration of the capsule upon impact, a very high value pointed to a rapid decrease in velocity, indicating a severe collision.

Moreover, expressing acceleration in terms of gravity (\( g \)) offers a familiar comparative scale, where \( g = 9.81 \, \text{m/s}^2 \). In our problem, the deceleration was tremendous at approximately \( -469.6g \), illustrating how much more forceful the crash impact was compared to Earth's gravitational pull.
  • Gravitational Acceleration \( g \): The acceleration due to Earth's gravity.
  • Deceleration: Negative acceleration; it indicates slowing down.
  • Comparative Scale: Measuring high acceleration values in \( g \)'s helps conceptualize the forces.
Impact Force Calculation
Impact force calculation is crucial for understanding how strong forces can be during collisions. Using Newton's second law, the force exerted by the ground on the crashing capsule can be calculated.

The impact force in this scenario was determined by multiplying the mass of the capsule by its deceleration. Implementing this gives the substantial force value experienced during the crash.

However, it's also insightful to express this force as a multiple of the capsule's weight. The weight of an object is the force due to gravity and is given by: \( W = mg \). In our problem, finding the impact force as a multiple of the capsule's weight revealed a factor of \( 469.6 \), underscoring the violent nature of the impact.
  • Importance: Understanding impact forces can be crucial for design and safety considerations.
  • Weight: The gravitational force exerted on an object's mass.
  • Intensity: Greater multiplication of weight indicates higher impacts, thus more structural damage.

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

An \(85-N\) box of oranges is being pushed across a horizontal floor. As it moves, it is slowing at a constant rate of 0.90 \(\mathrm{m} / \mathrm{s}\) each second. The push force has a horizontal component of 20 \(\mathrm{N}\) and a vertical component of 25 \(\mathrm{N}\) downward. Calculate the coefficient of kinetic friction between the box and floor.

Two 25.0 -N weights are suspended at opposite ends of a rope that passes over a light, frictionless pulley. The pulley is attached to a chain that goes to the ceiling. (a) What is the tension in the rope? (b) What is the tension in the chain?

A model airplane with mass 2.20 \(\mathrm{kg}\) moves in the \(x y\) -plane such that its \(x-\) and \(y\) -coordinates vary in time according to \(x(t)=\alpha-\beta t^{3}\) and \(y(t)=y t-\delta t^{2},\) where \(\alpha=1.50 \mathrm{m}, \beta=\) \(0.120 \mathrm{m} / \mathrm{s}^{3}, \gamma=3.00 \mathrm{m} / \mathrm{s},\) and \(\delta=1.00 \mathrm{m} / \mathrm{s}^{2} .\) (a) Calculate the \(x-\) and \(y\) -components of the net force on the plane as functions of time. (b) Sketch the trajectory of the airplane between \(t=0\) and \(t=3.00 \mathrm{s}\) , and draw on your sketch vectors showing the net force on the airplane at \(t=0, t=1.00 \mathrm{s}, t=2.00 \mathrm{s},\) and \(t=3.00 \mathrm{s}\) . For each of these times, relate the direction of the net force to the direction that the airplane is turning, and to whether the airplane is speeding up or slowing down (or neither). (c) What are the magnitude and direction of the net force at \(t=3.00 \mathrm{s} ?\)

A picture frame hung against a wall is suspended by two wires attached to its upper corners. If the two wires make the same angle with the vertical, what must this angle be if the tension in each wire is equal to 0.75 of the weight of the frame? (lanore any friction between the wall and the picture frame.)

The "Giant Swing" at a county fair consists of a vertical central shaft with a number of horizontal arms attached at its upper end (Fig. 5.57\()\) . Each arm supports a seat suspended from a cable 5.00 \(\mathrm{m}\) long, the upper end of the cable being fastened to the arm at a point 3.00 \(\mathrm{m}\) from the central shaft. (a) Find the time of one revolution of the swing if the cable supporting a seat makes an angle of \(30.0^{\circ}\) with the vertical. (b) Does the angle depend on the weight of the passenger for a given rate of revolution? figure can't copy

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.