(a) Explanation Given info: The mass of the car is 1500 kg , the mass of the brakes is 6.00 kg , the velocity of the before the brakes was applied 25.0 m / s , the initial temperature of the brakes is 20.0 ° C ., the internal energy of the system is transformed into the brakes whenever the car stops. The specific heat of the aluminum brakes is 900 J / kg ⋅ °C , the melting point for aluminum is 660 ° C . The formula to calculate the internal energy in brakes is E int = m b c Δ T Here, E int is the internal energy of the system. m b mass of the brakes. c is the specific heat of the aluminum brakes. Δ T is change in temperature. The change in the temperature is the (final melting temperature – the initial temperature) Therefore Δ T = 660°C − 20 .0°C Consider n be the number of times car stopped so n number of times the kinetic energy of the system was transferred in to the brakes. Thus calculate the value of n for which the n times the kinetic energy was stored in the internal energy of the system that is n times the kinetic energy is equal to internal energy n K = E int Here, K is the kinetic energy of the car. Substitute m b c Δ T for E int in equation (1) n K = m b c Δ T (1 The formula to calculate the kinetic energy of the car is K = 1 2 m c v 2 (2) Here, m c is the mass of the car v is the velocity of car (b) To determine The important aspect ignored in part (a) which will be considered in realistic approach.

Physics for Scientists and Engineers, Technology Update (No access codes included)

9th Edition

ISBN: 9781305116399

Author: Raymond A. Serway, John W. Jewett

Publisher: Cengage Learning

See similar textbooks

Concept explainers

Latent heat and phase change

A physical process in which a conversion among the basic states or phases of matter, i.e., solid, liquid, and gas takes place under the effect of a certain temperature and pressure is referred to as a phase change. Generally, the phase change of a substa…

Triple Point of Water

The branch of physics in which observer deals with temperature related properties is called thermodynamics.

Boiling Point of Water

Everyday examples of boiling is, boiling milk, heating water. One would have observed that when we heat water it goes through various stages and at one point bubbles show in water, and water keeps splashing with bubbles bursting, we in layman terms say t…

Freezing Point of Water

In general, the freezing point of water is 0° Celsius, or 32° Fahrenheit. This is the temperature at which water will ordinarily change from its liquid state to its solid state (ice). However, there are certain conditions that can affect the freezing poi…

Question

Chapter 20, Problem 20.24P

(a)

To determine

The number of stops the car made before the brakes start to melt.

(b)

To determine

The important aspect ignored in part (a) which will be considered in realistic approach.

Expert Solution & Answer

Chapter 20 Solutions

Physics for Scientists and Engineers, Technology Update (No access codes included)

Ch. 20 - Prob. 20.1QQ Ch. 20 - Suppose the same process of adding energy to the...Ch. 20 - Prob. 20.3QQ Ch. 20 - Characterize the paths in Figure 19.12 as...Ch. 20 - Prob. 20.5QQ Ch. 20 - An ideal gas is compressed to half its initial...Ch. 20 - A poker is a stiff, nonflammable rod used to push...Ch. 20 - Assume you are measuring the specific heat of a...Ch. 20 - Prob. 20.4OQ Ch. 20 - Prob. 20.5OQ

Knowledge Booster

Learn more about

Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, physics and related others by exploring similar questions and additional content below.

The number of stops the car made before the brakes start to melt.

Solution Summary: The author explains how the internal energy of the system is transformed into the brakes whenever the car stops.

Concept explainers

The number of stops the car made before the brakes start to melt.

The important aspect ignored in part (a) which will be considered in realistic approach.

Chapter 20 Solutions