Concept explainers
(a)
The constant friction force for the last
(a)
Answer to Problem 25AP
The constant friction force for the last
Explanation of Solution
The mass of the empty car is
Write the formula to calculate the energy by equation of motion
Here,
The formula of initial kinetic energy is,
Substitute
The formula of kinetic energy at final point
Substitute
The formula of the potential energy at start
Substitute
The formula of the potential energy at final point
Substitute
The formula of the energy wasted due to friction
Substitute
Substitute
Conclusion:
Substitute
Therefore, the constant friction force for the last
(b)
The highest speed reached by the car.
(b)
Answer to Problem 25AP
The highest speed reached by the car is
Explanation of Solution
The formula of kinetic energy at final point
The body is at the lowest point so the resistive force is taken upto that point only.
The formula of the energy wasted due to friction
Substitute
Write the formula to calculate the final velocity from equation (1) can be written as,
Conclusion:
Substitute
Therefore, the highest speed reached by the car is
(c)
The new values of friction force and highest speed when the weight is
(c)
Answer to Problem 25AP
The new value of friction force is
Explanation of Solution
The mass of the empty car is
The Write the formula to calculate the
Substitute
To calculate the final velocity the equation (2)
Substitute
Conclusion:
Therefore, the new value of friction force is
(d)
The depth of the underground part of the ride.
(d)
Answer to Problem 25AP
The depth of the underground part of the ride is
Explanation of Solution
Consider
The formula of the potential energy at start
Substitute
The Write the formula to calculate the depth
Conclusion:
Substitute
Therefore, the depth of the underground part of the ride is
(e)
The depth of the underground provided is feasible or not.
(e)
Answer to Problem 25AP
No, the depth of the underground provided is not feasible.
Explanation of Solution
No the depth of the underground tunnel provided is not feasible as the total length covered by the car is increased due to which the loss of energy due to friction is increased a lot as compared to the case when the underground path was not there. The non-conventional forces on the car are increased due to the depth provided as the friction in the path of later
Conclusion:
Therefore, the depth of the underground provided is not feasible.
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Chapter 8 Solutions
Physics for Scientists and Engineers
- To give a pet hamster exercise, some people put the hamster in a ventilated ball andallow it roam around the house(Fig. P13.66). When a hamsteris in such a ball, it can cross atypical room in a few minutes.Estimate the total kinetic energyin the ball-hamster system. FIGURE P13.66 Problems 66 and 67arrow_forwardA block is placed on top of a vertical spring, and the spring compresses. Figure P8.24 depicts a moment in time when the spring is compressed by an amount h. a. To calculate the change in the gravitational and elastic potential energies, what must be included in the system? b. Find an expression for the change in the systems potential energy in terms of the parameters shown in Figure P8.24. c. If m = 0.865 kg and k = 125 N/m, find the change in the systems potential energy when the blocks displacement is h = 0.0650 m, relative to its initial position. FIGURE P8.24arrow_forwardAn inclined plane of angle = 20.0 has a spring of force constant k = 500 N/m fastened securely at the bottom so that the spring is parallel to the surface as shown in Figure P6.61. A block of mass m = 2.50 kg is placed on the plane at a distance d = 0.300 m from the spring. From this position, the block is projected downward toward the spring with speed v = 0.750 m/s. By what distance is the spring compressed when the block momentarily comes to rest?arrow_forward
- An inclined plane of angle = 20.0 has a spring of force constant k = 500 N/m fastened securely at the bottom so that the spring is parallel to the surface as shown in Figure P7.47. A block of mass m = 2.50 kg is placed on the plane at a distance d = 0.300 m from the spring. From this position, the block is projected downward toward the spring with speed v = 0.750 m/s. By what distance is the spring compressed when the block momentarily comes to rest? Figure P7.47 Problems 47 and 48.arrow_forwardEstimate the kinetic energy of the following: a. An ant walking across the kitchen floor b. A baseball thrown by a professional pitcher c. A car on the highway d. A large truck on the highwayarrow_forwardWhy is the following situation impossible? In a new casino, a supersized pinball machine is introduced. Casino advertising boasts that a professional basketball player can lie on top of the machine and his head and feet will not hang off the edge! The ball launcher in the machine sends metal balls up one side of the machine and then into play. The spring in the launcher (Fig. P6.60) has a force constant of 1.20 N/cm. The surface on which the ball moves is inclined = 10.0 with respect to the horizontal. The spring is initially compressed its maximum distance d = 5.00 cm. A ball of mass 100 g is projected into play by releasing the plunger. Casino visitors find the play of the giant machine quite exciting.arrow_forward
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