
Concept explainers
(a)
Prove that the maximum stretching of spring from mean position is x=μsmgk.
(a)

Answer to Problem 60P
It is proved that the maximum stretching of spring from mean position is x=μsmgk.
Explanation of Solution
Write the relation between force on spring and maximum static frictional force.
kx=μsn
Here, k is the spring force, x is the displacement of spring, μs is the coefficient of static friction, and n is the normal reaction force.
Write the expression for n.
n=mg
Here, m is the mass of block and g is the gravitational acceleration.
Rewrite the first equation by substituting the above one.
kx=μsmg
Conclusion:
Rewrite the expression for x.
x=μsmgk
Therefore, it is proved that the maximum stretching of spring from mean position is x=μsmgk.
x=μsmgk.
(b)
Prove that block oscillates about mean point when spring is stretched by x=μsmgk.
(b)

Answer to Problem 60P
It is proved that block oscillates about mean point when spring is stretched by x=μsmgk.
Explanation of Solution
The block will be almost at rest at the break point because of the smaller value of velocity. The block starts to oscillate s soon when the force on block becomes −kx and +μkmg. Write the expression for net force on block while sliding.
Fnet=−kx+μkmg
Here, Fnet is the net force on block,.
Rewrite the above equation by multiplying and dividing the second term with k.
Fnet=−kx+kμkmgk=−k(x−μkmgk)
Express the term μkmgk into a single variable.
x−μkmgk=xrel
Here, xrel is the displacement of block from the point μkmgk.
Rewrite the expression for Fnet by substituting the above relation.
Fnet=−k(xrel)
Conclusion:
From the above calculation, it is evident that block starts to be in simple harmonic motion about mean position on displacing the spring
Therefore, it is proved that block oscillates about mean point when spring is stretched by x=μsmgk.
(c)
Plot the variation of position of block with time.
(c)

Answer to Problem 60P
The plot is
Explanation of Solution
The graph is plotted with time on x-axis and position on y-axis.
The dotted line along x-axis denotes the function xrel=μkmgk. The peak on curve denotes x=μsmgk
Conclusion:
Therefore, the graph is plotted
(d)
Prove that the amplitude of oscillation is A=(μs−μk)mgk.
(d)

Answer to Problem 60P
It is proved that the amplitude of oscillation is A=(μs−μk)mgk.
Explanation of Solution
Write the expression for xrel from part (b).
xrel=x−μkmgk
Rewrite the above expression by substituting μsmgk for x.
xrel=μsmgk−μkmgk=(μs−μk)mgk
Amplitude is the maximum displacement from the mean position only. Rewrite the expression as amplitude.
A=(μs−μk)mgk
Here, A is the amplitude.
On pulling the block to distance x=μsmgk, it will start to oscillate about x=μkmgk.
Conclusion:
Therefore, it is proved that the amplitude of oscillation is A=(μs−μk)mgk.
(e)
Prove that the period of oscillation is T=2(μs−μk)mgvk+π√mk.
(e)

Answer to Problem 60P
It is proved that the period of oscillation is T=2(μs−μk)mgvk+π√mk.
Explanation of Solution
Write the expression for time taken by block to move with the board
T1=2Av
Here, T1 is the time period and v is the speed of motion.
Rewrite the expression by substituting (μs−μk)mgk for A.
T1=2((μs−μk)mgk)v
Time taken by block to move from mean position to an extreme position.
T1/2=12(2π√mk)=π√mk
Here, T1/2 is the time taken to complete the half of SHM (same as that of time needed to spring back the block to original position.
The period of oscillation is the sum of T1 and T1/2.
T=T1+T1/2
Here, T is the time period of oscillation.
Conclusion:
Rewrite the above equation by substituting the relations for T1 and T1/2.
T=2((μs−μk)mgk)v+π√mk=2((μs−μk)mg)kv+π√mk
Therefore, It is proved that the period of oscillation is T=2(μs−μk)mgvk+π√mk.
Want to see more full solutions like this?
Chapter 12 Solutions
Principles of Physics: A Calculus-Based Text
- (a) For a spherical capacitor with inner radius a and outer radius b, we have the following for the capacitance. ab C = k₂(b- a) 0.0695 m 0.145 m (8.99 × 10º N · m²/c²)( [0.145 m- 0.0695 m × 10-11 F = PF IIarrow_forwardA pendulum bob A (0.5 kg) is given an initialspeed of vA = 4 m/s when the chord ishorizontal. It then hits a stationary block B (1kg) which then slides to a maximum distanced before it stops. Determine the value of d.The coefficient of static friction between theblock and the plane is μk = 0.2. The coefficientof restitution between A and B is e = 0.8.Ans: d=1.0034 marrow_forwardFigure 29-43 Problem 12. ••13 In Fig. 29-44, point P₁ is at distance R = 13.1 cm on the perpendicular bisector of a straight wire of length L = 18.0 cm carrying current i = 58.2 mA. (Note that the wire is not long.) What is the magnitude of the magnetic field at P₁ due to i? P2° R R Larrow_forward
- Checkpoint 1 The figure shows the current i in a single-loop circuit with a battery B and a resistance R (and wires of neg- ligible resistance). (a) Should the emf arrow at B be drawn pointing leftward or rightward? At points a, B C R b, and c, rank (b) the magnitude of the current, (c) the electric potential, and (d) the electric potential energy of the charge carriers, greatest first.arrow_forwardPls help ASAParrow_forwardPls help asaparrow_forward
- Physics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage LearningPrinciples of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningPhysics for Scientists and Engineers, Technology ...PhysicsISBN:9781305116399Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning
- Classical Dynamics of Particles and SystemsPhysicsISBN:9780534408961Author:Stephen T. Thornton, Jerry B. MarionPublisher:Cengage LearningPhysics for Scientists and EngineersPhysicsISBN:9781337553278Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningPhysics for Scientists and Engineers with Modern ...PhysicsISBN:9781337553292Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning





