
Concept explainers
(a)
Check whether the 5.0 N force is enough to put the puck into motion.
(a)

Answer to Problem 61P
5.0 N force is not enough to put the puck into motion.
Explanation of Solution
Puck will start to move if the applied force is greater than the static frictional force. Write the equation to find the static frictional force.
fst=μsmg
Here, fst is the static frictional force, μs is the coefficient of static friction, m is the mass of puck and g is the gravitational acceleration.
Conclusion:
Substitute 0.35 for μs, 2.0 kg for m and 9.8 m/s2 for g in the above equation to find fst.
fst=(0.35)(2.0 kg)(9.8 m/s2)=6.86 N
From the calculation, it is evident that the applied force 5.0 N is lesser than that of the static frictional force. So, the puck cannot move.
Thus, 5.0 N force is not enough to put the puck into motion.
(b)
Check whether the sudden increase in applied force to 7.5 N force while pushing can put the puck into motion or not.
(b)

Answer to Problem 61P
The 7.5 N force can put the puck into motion.
Explanation of Solution
Puck will start to move if the force is greater than the kinetic frictional force. Write the equation to find the kinetic frictional force.
fk=μkmg (I)
Here, fk is the kinetic frictional force, μk is the coefficient of kinetic friction, m is the mass of puck and g is the gravitational acceleration.
Conclusion:
Substitute 0.25 for μk, 2.0 kg for m and 9.8 m/s2 for g in the above equation to find fk.
fk=(0.25)(2.0 kg)(9.8 m/s2)=4.9 N
From the calculation, it is evident that the applied force 7.5 N is greater than that of the kinetic frictional force. So, the puck will move.
Thus, the 7.5 N force can put the puck into motion.
(c)
The acceleration of puck.
(c)

Answer to Problem 61P
Acceleration will be 0.55 m/s2.
Explanation of Solution
Write the relation between applied
F−fk=ma
Here, F is the applied force and a is the acceleration.
Conclusion:
Substitute 6.0 N for F, 4.9 N for f and 2.0 kg for m in the above equation to find a.
6.0 N−4.9 N=(2.0 kg)a1.1 N=(2.0 kg)aa=1.1 N2.0 kg=0.55 m/s2
Thus, the acceleration will be 0.55 m/s2.
(d)
The acceleration of puck in moon and state the reason for difference, if any.
(d)

Answer to Problem 61P
Acceleration will be 2.6 m/s2 which is higher than that in earth and the reason is that the lesser value of gravitational acceleration on moon creates only less frictional force.
Explanation of Solution
Write the equation to find the kinetic frictional force in moon.
fk=μkmgmoon
Here, gmoon is the gravitational acceleration in moon.
Conclusion:
Substitute 0.25 for μk, 2.0 kg for m and 1.6m/s2 for g in the above equation to find fk.
fk=(0.25)(2.0 kg)(1.6 m/s2)=0.8 N
Substitute 6.0 N for F, 0.8 N for fk and 2.0 kg for m in equation (I) to find a.
6.0 N−0.8 N=(2.0 kg)a5.2 N=(2.0 kg)aa=5.2 N2.0 kg=2.6 m/s2
The acceleration of puck with same applied force in moon is much higher than that on Earth. The reason is that the acceleration due to gravity on moon is only 1/6th of Earth. It results in less frictional force on moon. As a result, acceleration will be more.
Thus, the acceleration will be 2.6 m/s2 which is higher than that in earth and the reason is that the lesser value of gravitational acceleration on moon creates only less frictional force.
Want to see more full solutions like this?
Chapter 3 Solutions
COLLEGE PHYSICS-CONNECT ACCESS
- The rectangular loop of wire shown in the figure (Figure 1) has a mass of 0.18 g per centimeter of length and is pivoted about side ab on a frictionless axis. The current in the wire is 8.5 A in the direction shown. Find the magnitude of the magnetic field parallel to the y-axis that will cause the loop to swing up until its plane makes an angle of 30.0 ∘ with the yz-plane. Find the direction of the magnetic field parallel to the y-axis that will cause the loop to swing up until its plane makes an angle of 30.0 ∘ with the yz-plane.arrow_forwardA particle with a charge of − 5.20 nC is moving in a uniform magnetic field of (B→=−( 1.22 T )k^. The magnetic force on the particle is measured to be (F→=−( 3.50×10−7 N )i^+( 7.60×10−7 N )j^. Calculate the y and z component of the velocity of the particle.arrow_forwardneed answer asap please thank youarrow_forward
- 3. a. Determine the potential difference between points A and B. b. Why does point A have a higher potential energy? Q = +1.0 C 3.2 cm 4.8 cm Aarrow_forwardPls help ASAParrow_forward1. Explain the difference between electrical field, potential difference, and electrical potential differencearrow_forward
- Pls help ASAParrow_forward9. When an electron moves into a uniform and perpendicular magnetic field, it will.. a. Accelerate parallel to the magnetic Field until it leaves b. Accelerate in a circular path c. Accelerate perpendicular to both the magnetic field and its original direction d. Repel back into the electric field 10. If a proton at rest is placed in a uniform magnetic field with no electric or gravitational field around, the proton will…….. a. Accelerate in the direction of the magnetic field b. Accelerate in a direction perpendicular to the magnetic field c. Move in a circular path d. Not acceleratearrow_forward7. The electric field at a distance of 1.0 mfrom a charged sphere is 100 N/C. At what distance from thesphere will the electric field be 50 N/C? a. 1.1 m b. 1.4 m c. 2.0 m d. 4.0 m 8. The electric potential due to a point charge at a point depends on a. The direction of the electric field b. The distance from the point charge c. The velocity of the point charge d. The mass of the point chargearrow_forward
- College PhysicsPhysicsISBN:9781305952300Author:Raymond A. Serway, Chris VuillePublisher:Cengage LearningUniversity Physics (14th Edition)PhysicsISBN:9780133969290Author:Hugh D. Young, Roger A. FreedmanPublisher:PEARSONIntroduction To Quantum MechanicsPhysicsISBN:9781107189638Author:Griffiths, David J., Schroeter, Darrell F.Publisher:Cambridge University Press
- Physics for Scientists and EngineersPhysicsISBN:9781337553278Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningLecture- Tutorials for Introductory AstronomyPhysicsISBN:9780321820464Author:Edward E. Prather, Tim P. Slater, Jeff P. Adams, Gina BrissendenPublisher:Addison-WesleyCollege Physics: A Strategic Approach (4th Editio...PhysicsISBN:9780134609034Author:Randall D. Knight (Professor Emeritus), Brian Jones, Stuart FieldPublisher:PEARSON





