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Get college assignment help at uniessay writers Susan’s 12.0 kg baby brother Paul sits on a mat. Susan pulls the mat across the floor using a rope that is angled 30 degrees above the floor. The tension is a constant 30.0 N and the coefficient of friction is 0.200. Use work and energy to find Paul’s speed after being pulled 2.90 m.

1. Metabolizing a candy bar releases about 106 joules. How fast must the candy bar travel to have the same 106 joules in the form of kinetic energy? (Assume the candy bar’s mass is 0.2 kg.)

A student (m = 64 kg) falls freely from rest and strikes the ground. During the collision with the ground, he comes to rest in a time of 0.04 s. The average force exerted on him by the ground is 18000 N, where the upward direction is taken to be the positive direction. From what height did the student fall? Assume that the only force acting on him during the collision is that due to the ground.

magine a frictionless pulley (a solid cylinder) of unknown mass M and radius r = 0.200 m which is used to draw water from a well. A bucket of mass m = 1.50 kg is attached to a massless cord wrapped around the pulley. The bucket starts from rest at the top of the well and falls for t = 3.00 s before hitting the water h = 6.39 m below the top of the well.

You fire a gun horizontally that is 25.0 m off the ground and the bullet goes at 200.0 m/s. What is the time it takes for the bullet to hit the ground, how far down range does the bullet travel, and what is the resultant velocity (in m/s) and final angle?

if under white light one looks at a film that has a refractive index of 1.333 and thickness of 183nm, which color is missing from the light reflected from the film

A 0.450-kg ball is dropped from rest at a point 1.30 m above the floor. The ball rebounds straight upward to a height of 0.700 m. What are the magnitude and direction of the impulse of the net force applied to the ball during the collision with the floor?

A 0.30 kg softball has a velocity of 12 m/s at an angle of 35Â° below the horizontal just before making contact with the bat. The ball leaves the bat 2.0 ms later with a vertical velocity of magnitude 10 m/s. What is the magnitude of the average force of the bat on the ball during the ball-bat contact?

Three equal point charges, each with charge 1.80 , are placed at the vertices of an equilateral triangle whose sides are of length 0.400 . What is the electric potential energy of the system? (Take as zero the potential energy of the three charges when they are infinitely far apart.) Use = 8.85×10−12 for the permittivity of free space.

Chapter 15 Homework Question 1 A particle is in simple harmonic motion with period T. At time t = 0 it is at the equilibrium point. At which of the following times is it furthest from the equilibrium point? 0.7T 0.5T T 1.4T 1.5T Question 2 The acceleration of a body executing simple harmonic motion leads the velocity by what phase? 0 Pi/8 rad Pi/4 rad Pi/2 rad Pirad Question 3 The displacement of an object oscillating on a spring is given by x(t) = xmcos( t ). If the initial displacement is zero and the initial velocity is in the negative x direction, then the phase constant is: 0 Pi/2 radians Pi radians 3Pi /2 radians 2 Pi radians Question 4 The displacement of an object oscillating on a spring is given by x(t) = xmcos( t ). If the object is initially displaced in the negative x direction and given a negative initial velocity, then the phase constant is between: 0 and Pi/2 radians Pi/2 and Pi radians Pi and 3 Pi/2 radians 3 Pi/2 and 2 Pi radians none of the above ( is exactly 0, /2, , or 3 /2 radians) Question 5 A certain spring elongates 9 mm when it is suspended vertically and a block of mass M is hung on it. The natural frequency of this mass-spring system is: is 0.088 rad/s is 33 rad/s is 200 rad/s is 1140 rad/s cannot be computed unless the value of M is given Question 6 A 0.20-kg object mass attached to a spring whose spring constant is 500 N/m executes simple harmonic motion. If its maximum speed is 5.0 m/s, the amplitude of its oscillation is: Print Assignment: Chapter 15 Homework ::true http://edugen.wiley.com/edugen/shared/assignment/test/agprint.uni?numb… 2 of 8 11/2/2010 2:15 PM 0.0020 m 0.10 m 0.20 m 25 m 250 m Question 7 A 0.25-kg block oscillates on the end of the spring with a spring constant of 200 N/m. If the oscillation is started by elongating the spring 0.15 m and giving the block a speed of 3.0 m/s, then the maximum speed of the block is: 0.13 m/s 0.18 m/s 3.7 m/s 5.2 m/s 13 m/s Question 8 A 0.25-kg block oscillates on the end of the spring with a spring constant of 200 N/m. If the oscillation is started by elongating the spring 0.15 m and giving the block a speed of 3.0 m/s, then the amplitude of the oscillation is: 0.13 m 0.18 m 3.7 m 5.2 m 13 m Question 9 A block attached to a spring undergoes simple harmonic motion on a horizontal frictionless surface. Its total energy is 50 J. When the displacement is half the amplitude, the kinetic energy is: zero 12.5 J 25 J 37.5 J 50 J Question 10 A mass-spring system is oscillating with amplitude A. The kinetic energy will equal the potential energy only when the displacement is zero ± A/4 ± A/2 ± A/rad from 2 anywhere between –A and A *Question 11 What is the maximum acceleration of a platform that oscillates with an amplitude of 2.8 cm at a frequency of 5.2 Hz? Number________ *1 Units_________ Significant digits are disabled; the tolerance is /-2% *Question 12 In Fig. 15-29, two identical springs of spring constant 160 N/m are attached to a block of mass 23 kg. The block is set oscillating on the frictionless floor. What is the frequency (in Hz) of oscillation? Number________ *1 Units__________ *Question 13 An oscillator consists of a block of mass 0.493 kg connected to a spring. When set into oscillation with amplitude 35 cm, the oscillator repeats its motion every 0.439 s. Find the (a) period, (b) frequency (in Hz), (c) angular frequency, (d) spring constant, (e) maximum speed, and (f) magnitude of the maximum force on the block from the spring. (a) Number________ *1 Units________ (b) Number________ *2 Units________ (c) Number________ *3 Units_________ (d) Number________ *4 Units_________ (e) Number_________ *5 Units________ (f) Number *6 Units *Question 14 An oscillator consists of a block attached to a spring (k = 372 N/m). At some time t, the position (measured from the system’s equilibrium location), velocity, and acceleration of the block are x = 0.101 m, v = -19.1 m/s, and a = -122 m/s2. Calculate (a) the frequency (in Hz) of oscillation, (b) the mass of the block, and (c) the amplitude of the motion. (a) Number________ *1 Units____________ (b) Number________ *2 Units____________ (c) Number________ *3 Units____________ *Question 15 When the displacement in SHM is equal to 1/7 of the amplitude xm, what fraction of the total energy is (a) kinetic energy and (b) potential energy? (c) At what displacement, in terms of the amplitude, is the energy of the system half kinetic energy and half potential energy? (Give the ratio of the answer to the amplitude) (a)__________ *1 (b)__________ *2 (c)__________ *3 *Question 16 A block of mass M = 5.10 kg, at rest on a horizontal frictionless table, is attached to a rigid support by a spring of constant k = 5780 N/m. A bullet of mass m = 8.50 g and velocity of magnitude 530 m/s strikes and is embedded in the block (Fig. 15-38). Assuming the compression of the spring is negligible until the bullet is embedded, determine the amplitude of the resulting simple harmonic motion. Number______________ *1 Units_______________ Significant digits are disabled; the tolerance is /-2% *Question 17 If the phase angle for a block-spring system in SHM is π/8 rad and the block’s position is given by x = xmcos(ωt φ), what is the ratio of the kinetic energy to the potential energy at time t = 0? Number *1 Units Significant digits are disabled; the tolerance is /-2% *Question 18 A 81 kg solid sphere with a 15 cm radius is suspended by a vertical wire. A torque of 0.25 Nm is required to rotate the sphere through an angle of 0.76 rad and then maintain that orientation. What is the period of the oscillations that result when the sphere is then released? Number_________ *1 Units_____________ Significant digits are disabled; the tolerance is /-2% *Question 19 The pendulum in Fig. 15-40 consists of a uniform disk with radius r = 17.0 cm and mass 570 g attached to a uniform rod with length L = 520 mm and mass 230 g. (a) Calculate the rotational inertia of the pendulum about the pivot point. (b) What is the distance between the pivot point and the center of mass of the pendulum? (c) Calculate the period of oscillation. (a) Number________ *1 Units_________ (b) Number________ *2 Units____________ (c) Number________ *3 Units_________ *Question 20 Suppose that a simple pendulum consists of a small 70.0 g bob at the end of a cord of negligible mass. If the angle θ between the cord and the vertical is given by θ = (0.0781 rad) cos[(1.17 rad/s) t φ], what are (a) the pendulum’s length and (b) its maximum kinetic energy? (a) Number______________ *1 Units__________ (b) Number_______________ *2 Units___________ *Question 21 In Fig. 15-44, a stick of length L = 1.5 m oscillates as a physical pendulum. (a) What value of distance x between the stick’s center of mass and its pivot point O gives the least period? (b) What is that least period? (a) Number________________ *1 Units__________ (b) Number________________ *2 Units__________ *Question 22 A 1500 kg car carrying four 94 kg people travels over a “washboard” dirt road with corrugations 4.4 m apart. The car bounces with maximum amplitude when its speed is 19 km/h. When the car stops, and the people get out, by how much does the car body rise on its suspension? Number __________ *1 Units______________

Get college assignment help at uniessay writers A car (mass= 1100 kg) is traveling at 32 m/s when it collides head-on with a sport utiliity vehicle (mass = 2500kg) traveling in the opposite direction. in a collision, the two vehicles come to a halt, at what speed was the sport utility vehicle traveling

A carpenter places a board weighing 30 lb on the edge of the roof 24 ft above the ground. How much potential energy does the board have in relation to the ground? Answer in units of ft · lb.

A two-ended “rocket” that is initally stationary on a frictionless floor, with its center a the origin of an x axis. The rocket consists of a central block C(of mass M = 6.00kg) and blocks L and R (each of mass m = 2.00kg) on the left and right sides. Small explosions can shoot either of teh side blocks away fro mblock C and along the x axis. Here is the sequence: (1) At time t = 0, block L is shot to the left with a speed of 3.00 m/s relative to the velocity that the explosion gives the rest of the rocket. (2) Next at the time t = .80 s, block R is shot to the right with a speed of 3m/s relative to the velocity that block C then has. At t = 2.80s, what are the (a) velocity of block C and (b) the position of its center?

Jack and Jill ran up the hill at 3.3 {rm m}/{rm s}. The horizontal component of Jill’s velocity vector was 2.2 {rm m}/{rm s}. What was the angle of the hill?

What is the magnitude of the ball’s total displacement, in centimeters?

A spring is hung from the ceiling. A 0.4-kg block is then attached to the free end of the spring. When released from rest, the block drops 0.17 m before momentarily coming to rest. What is the spring constant of the spring

As a comet swings around the Sun, ice on the comet’s surface vaporizes, releasing trapped dust particles and ions. The ions, because they are electrically charged, are forced by the electrically charged solar wind into a straight ion tail that points radially away from the Sun (Fig. 33-1). The (electrically neutral) dust particles are pushed radially outward from the Sun by the radiation force on them from sunlight. Assume that the dust particles are spherical, have density × kgm , and are totally absorbing. (a) What radius must a particle have in order to follow a straight path, like path 2 in the figure? (b) If its radius is larger, does its path curve away from the Sun

A projectile is fired straight upward at 134 m/s. How fast is it moving at the instant it reaches the top of its trajectory? 1 m/s Suppose instead it were fired upward at 37°. What would be its speed at the top of its trajectory? 2 m/s

a skier with mass of 80.0 kg starts from rest and skis down a slop from an elevation of 110.0 m. The speed of the skier at the bottom of the slope is 20.0 m/s. How much work is done by the nonconservative force of friction?

A 2.00 m tall basketball player wants to make a goal from 10.0 m from the basket, as in Figure P3.58. If he shoots the ball at a 45.0° angle, at what initial speed must he throw the basketball so that it goes through the hoop without striking the backboard?

A loudspeaker of mass 17.0 {rm kg} is suspended a distance of h = 1.80 {rm m} below the ceiling by two cables that make equal angles with the ceiling. Each cable has a length of l = 2.70 {rm m}. What is the tension T in each of the cables? Use 9.80 {rm m/s}^2 for the magnitude of the acceleration due to gravity.

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November 3, 2019