
Concept explainers
(a)
If the crate resting on the bed of a decelerating truck would slide during the braking period.

Answer to Problem 77QAP
The crate will not slide, since the acceleration it experiences due to the truck's deceleration is less than the acceleration it experiences due to the force of static friction.
Explanation of Solution
Given:
The mass of the crate
Initial velocity of the truck
Final velocity of the truck
Time during which the truck comes to a stop
Coefficient of static friction between the truck and the crate
Formula used:
To find if the crate would slide or not, a free body diagram is drawn for the crate and the force equations for equilibrium and for motion of the crate are determined.
The free body diagram for the crate is shown below:
The weight of the block
The block is in equilibrium along the vertical ( y ) direction.
Therefore,
Since,
Therefore,
If
If the force of friction produces an acceleration,
Write an expression for the acceleration due to the force of friction using equations (1) and (2).
The expression for the acceleration produced by the truck is given by,
Calculation:
Calculate the acceleration
Express the initial velocity of the crate in m/s.
Calculate the acceleration a experienced by the crate due to the truck's decoration by substituting the values of the variables in equation (4).
This acceleration acts along the −x direction.
The crate slides if a >af.
Conclusion:
It can be seen that the acceleration in the +x direction is 6.419 m/s2 and that along the −x direction is 1.158 m/s2. Since
(b)
The minimum stopping time for the truck, that prevents the crate from sliding.

Answer to Problem 77QAP
For the crate to not slide on the bed of the truck, the minimum stopping time of the truck is 2.16 s.
Explanation of Solution
Given:
Acceleration produced by the
Initial velocity of the truck
Final velocity of the truck
Formula used:
The crate will just remain in equilibrium, if the acceleration acting on it along the −x direction due to the truck's deceleration is equal to the acceleration along the +x direction due to the force of friction.
Calculation:
Rewrite the expression for
Substitute the values of the variables in the equation and solve for
Conclusion:
Thus, for the crate to not slide on the bed of the truck, the minimum stopping time of the truck is 2.16 s.
Want to see more full solutions like this?
Chapter 5 Solutions
COLLEGE PHYSICS
- a) Consider the following function, where A is a constant. y(x,t) = A(x — vt). Can this represent a wave that travels along? Explain. b) Which of the following are possible traveling waves, provide your reasoning and give the velocity of the wave if it can be a traveling wave. e-(a²x²+b²²-2abtx b.1) y(x,t) b.2) y(x,t) = = A sin(ax² - bt²). 2 b.3) y(x,t) = A sin 2π (+) b.4) y(x,t) = A cos² 2π(t-x). b.5) y(x,t) = A cos wt sin(kx - wt)arrow_forwardThe capacitor in (Figure 1) is initially uncharged. The switch is closed at t=0. Immediately after the switch is closed, what is the current through the resistor R1, R2, and R3? What is the final charge on the capacitor? Please explain all steps.arrow_forwardSuppose you have a lens system that is to be used primarily for 620-nm light. What is the second thinnest coating of fluorite (calcium fluoride) that would be non-reflective for this wavelength? × nm 434arrow_forward
- The angle between the axes of two polarizing filters is 19.0°. By how much does the second filter reduce the intensity of the light coming through the first? I = 0.106 40 xarrow_forwardAn oil slick on water is 82.3 nm thick and illuminated by white light incident perpendicular to its surface. What color does the oil appear (what is the most constructively reflected wavelength, in nanometers), given its index of refraction is 1.43? (Assume the index of refraction of water is 1.33.) wavelength color 675 × nm red (1 660 nm)arrow_forwardA 1.50 μF capacitor is charging through a 16.0 Ω resistor using a 15.0 V battery. What will be the current when the capacitor has acquired 1/4 of its maximum charge? Please explain all stepsarrow_forward
- In the circuit shown in the figure (Figure 1), the 6.0 Ω resistor is consuming energy at a rate of 24 J/s when the current through it flows as shown. What are the polarity and emf of the battery E, assuming it has negligible internal resistance? Please explain all steps. I know you need to use the loop rule, but I keep getting the answer wrong.arrow_forwardIf you connect a 1.8 F and a 2.6 F capacitor in series, what will be the equivalent capacitance?arrow_forwardSuppose that a particular heart defibrillator uses a 1.5 x 10-5 Farad capacitor. If it is charged up to a voltage of 7300 volts, how much energy is stored in the capacitor? Give your answer as the number of Joules.arrow_forward
- The voltage difference across an 8.3 nanometer thick cell membrane is 6.5 x 10-5volts. What is the magnitude of the electric field inside this cell membrane? (Assume the field is uniform, and give your answer as the number of Volts per meter... which is the same as the number of Newtons per Coulomb.)arrow_forwardThree identical capacitors are connected in parallel. When this parallel assembly of capacitors is connected to a 12 volt battery, a total of 3.1 x 10-5 coulombs flows through the battery. What is the capacitance of one individual capacitor? (Give your answer as the number of Farads.)arrow_forwardSuppose you construct your own capacitor by placing two parallel plates at a distance 0.27 meters apart. The plates each have a surface area of 0.64 square meters. What is the capacitance of this setup? (Give your answer as the number of Farads.)arrow_forward
- Classical Dynamics of Particles and SystemsPhysicsISBN:9780534408961Author:Stephen T. Thornton, Jerry B. MarionPublisher:Cengage LearningPrinciples of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningCollege PhysicsPhysicsISBN:9781938168000Author:Paul Peter Urone, Roger HinrichsPublisher:OpenStax College
- College PhysicsPhysicsISBN:9781305952300Author:Raymond A. Serway, Chris VuillePublisher:Cengage LearningPhysics for Scientists and Engineers with Modern ...PhysicsISBN:9781337553292Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningPhysics for Scientists and EngineersPhysicsISBN:9781337553278Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning





