Problem 7.1QQ Problem 7.2QQ: Figure 7.4 shows four situations in which a force is applied to an object. In all four cases, the... Problem 7.3QQ: Which of the following statements is true about the relationship between the dot product of two... Problem 7.4QQ: A dart is inserted into a spring-loaded dart gun by pushing the spring in by a distance x. For the... Problem 7.5QQ: A dart is inserted into a spring-loaded dart gun by pushing the spring in by a distance x. For the... Problem 7.6QQ: Choose the correct answer. The gravitational potential energy of a system (a) is always positive (b)... Problem 7.7QQ: A ball is connected to a light spring suspended vertically as shown in Figure 7.18. When pulled... Problem 7.8QQ: What does the slope of a graph of U(x) versus x represent? (a) the magnitude of the force on the... Problem 7.1OQ: Alex and John are loading identical cabinets onto a truck. Alex lifts his cabinet straight up from... Problem 7.2OQ: If the net work done by external forces on a particle is zero, which of the following statements... Problem 7.3OQ: A worker pushes a wheelbarrow with a horizontal force of 50 N on level ground over a distance of 5.0... Problem 7.4OQ: A cart is set rolling across a level table, at the same speed on every trial. If it runs into a... Problem 7.5OQ Problem 7.6OQ: Is the work required to be done by an external force on an object on a frictionless, horizontal... Problem 7.7OQ: A bloc k, of mass m is dropped from the fourth Moor of an office building and hits the sidewalk... Problem 7.8OQ: An a simple pendulum swings back and forth, the forces acting on the suspended object are (a) the... Problem 7.9OQ: Bullet 2 has twice the mass of bullet 1. Both are fired so that they have the same speed. If the... Problem 7.10OQ: Figure OQ7.10 shows a light extended spring exerting a force Fs to the left on a block. (i) Does the... Problem 7.11OQ: If the speed of a particle is doubled, what happens to its kinetic energy? (a) It becomes four times... Problem 7.12OQ Problem 7.13OQ Problem 7.14OQ: A certain spring that obeys Hookes law is stretched by an external agent. The work done in... Problem 7.15OQ: A cart is set rolling across a level table, al the same speed on every trial. If it runs into a... Problem 7.16OQ: An ice cube has been given a push and slides without friction on a level table. Which is correct?... Problem 7.1CQ: Can a normal force do work? If not, why not? If so, give an example. Problem 7.2CQ: Object 1 pushes on object 2 as the objects move together, like a bulldozer pushing a stone. Assume... Problem 7.3CQ: A student has the idea that the total work done on an object is equal to its final kinetic energy.... Problem 7.4CQ: (a) For what values of the angle between two vectors is their scalar product positive? (b) For what... Problem 7.5CQ Problem 7.6CQ: Discuss the work done by a pitcher throwing a baseball. What is the approximate distance through... Problem 7.7CQ Problem 7.8CQ: If only one external force acts on a particle, does it necessarily change the particles (a) kinetic... Problem 7.9CQ Problem 7.10CQ Problem 7.11CQ: A certain uniform spring has spring constant k. Now the spring is cut in half. What is the... Problem 7.12CQ Problem 7.13CQ: Does the kinetic energy of an object depend on the frame of reference in which its motion is... Problem 7.14CQ: Cite two examples in which a force is exerted on an object without doing any work on the object. Problem 7.1P: A shopper in a supermarket pushes a cart with a force of 35.0 N directed at an angle of 25.0 below... Problem 7.2P: A raindrop of mass 3.35 10-5 kg falls vertically at constant speed under the influence of gravity... Problem 7.3P: In 1990, Walter Arfeuille of Belgium lifted a 281.5-kg object through a distance of 17.1 cm using... Problem 7.4P: The record number of boat lifts, including the boat and its ten crew members, was achieved by Sami... Problem 7.5P: A block of mass m = 2.50 kg is pushed a distance d = 2.20 m along a frictionless, horizontal table... Problem 7.6P: Spiderman, whose mass is 80.0 kg, is dangling on the free end of a 12.0-m-long rope, the other end... Problem 7.7P Problem 7.8P: Vector A has a magnitude of 5.00 units, and vector B has a magnitude of 9.00 units. The two vectors... Problem 7.9P Problem 7.10P: Find the scalar product of the vectors in Figure P7.7. Figure P7.7 Problem 7.11P: A force F = (6i 2j) N acts on a panicle that under-goes a displacement r = (3i + j) m. Find (a) the... Problem 7.12P: Using the definition of the scalar product, find the angles between (a) A=3i2j and B=4i4j, (b)... Problem 7.13P: Lei B = 5.00 m at 60.0. Let the vector C have the same magnitude as A and a direction angle greater... Problem 7.14P: The force acting on a panicle varies as shown in Figure la P7.14. Find the work done by the force on... Problem 7.15P: A particle is subject to a force Fx that varies with position as shown in Figure P7.9. Find the work... Problem 7.16P: In a control system, an accelerometer consists of a 4.70-g object sliding on a calibrated horizontal... Problem 7.17P: When a 4.00-kg object is hung vertically on a certain light spring that obeys Hookes law, the spring... Problem 7.18P: Hookes law describes a certain light spring of unstretched length 35.0 cm. When one end is attached... Problem 7.19P: An archer pulls her bowstring back 0.400 m by exerting a force that increases uniformly from zero to... Problem 7.20P: A light spring with spring constant 1 200 N/m is hung from an elevated support. From its lower end... Problem 7.21P: A light spring with spring constant k1 is hung from an elevated support. From its lower end a second... Problem 7.22P: Express the units of the force constant of a spring in SI fundamental units. Problem 7.23P: A cafeteria tray dispenser supports a stack of trays on a shelf that hangs from four identical... Problem 7.24P: A light spring with force constant 3.85 N/m is compressed by 8.00 cm as it is held between a... Problem 7.25P: A small particle of mass m is pulled to the top of a friction less half-cylinder (of radius R) by a... Problem 7.26P: The force acting on a particle is Fx = (8x 16), where F is in newtons and x is in meters. (a) Make... Problem 7.27P: When different loads hang on a spring, the spring stretches to different lengths as shown in the... Problem 7.28P: A 100-g bullet is fired from a rifle having a barrel 0.600 m long. Choose the origin to be at the... Problem 7.29P: A force F = (4xi + 3yj), where F is in newtons and x and y are in meters, acts on an object as the... Problem 7.30P: Review. The graph in Figure P7.20 specifies a functional relationship between the two variables u... Problem 7.31P: A 3.00-kg object has a velocity (6.00i - 2.00j) m/s. a) What is its kinetic energy at this moment?... Problem 7.32P Problem 7.33P: A 0.600-kg particle has a speed of 2.00 m/s at point and kinetic energy of 7.50 J at point . What... Problem 7.34P: A 4.00-kg particle is subject to a net force that varies with position as shown in Figure P7.9. The... Problem 7.35P: A 2 100-kg pile driver is used to drive a steel I-beam into the ground. The pile driver falls 5.00 m... Problem 7.36P: Review. In an electron microscope, there is an electron gun that contains two charged metallic... Problem 7.37P: Review. You can think of the workkinetic energy theorem as a second theory of motion, parallel to... Problem 7.38P: Review. A 7.80-g bullet moving at 575 m/s strikes the hand of a superhero, causing the hand to move... Problem 7.39P: Review. A 5.75-kg object passes through the origin at time t = 0 such that its x component of... Problem 7.40P: A 1 000-kg roller coaster car is initially at the top of a rise, at point . It then moves 135 ft, at... Problem 7.41P: A 0.20-kg stone is held 1.3 m above the top edge of a water well and then dropped into it. The well... Problem 7.42P: A 400-N child is in a swing that is attached to a pair of ropes 2.00 in long. Find the gravitational... Problem 7.43P: A 4.00-kg particle moves from the origin to position , having coordinates x = 5.00 m and y = 5.00 m... Problem 7.44P: (a) Suppose a constant force acts on an object. The force does not vary with time or with the... Problem 7.45P: A force acting on a particle moving in the xy plane is given by F=(2yi+x2j), where F is in newtons... Problem 7.46P: An object moves in the xy plane 111 Figure P7.43 and experiences a friction force with constant... Problem 7.47P Problem 7.48P: Why is the following situation impossible? A librarian lifts a book from the ground to a high shelf,... Problem 7.49P: A potential energy function for a system in which a two-dimensional force acts is of the form U =... Problem 7.50P: A single conservative force acting on a particle within a system varies as F = ( Ax + Bx2)i where A... Problem 7.51P: A single conservative force acts on a 5.0-kg particle within a system due to its interaction with... Problem 7.52P: For the potential energy curve shown in Figure P7.38, (a) determine whether the force Fx is... Problem 7.53P: A right circular cone can theoretically be balanced on a horizontal surface in three different ways.... Problem 7.54AP: The potential energy function for a system of particles is given by U(x) = x3 + 2x2 + 3x, where x is... Problem 7.55AP Problem 7.56AP: A particle moves along the xaxis from x = 12.8 m to x = 23.7 m under the influence of a force... Problem 7.57AP: Two identical steel balls, each of diameter 25.4 nun and moving in opposite directions at 5 m/s, run... Problem 7.58AP: When an object is displaced by an amount x from stable equilibrium, a restoring force acts on it,... Problem 7.59AP: A 6 000-kg freight car rolls along rails with negligible friction. The car is brought to rest by a... Problem 7.60AP: Why is the following situation impossible? In a new casino, a supersized pinball machine is... Problem 7.61AP Problem 7.62AP: The spring constant of an automotive suspension spring increases with increasing load due to a... Problem 7.63AP: An inclined plane of angle = 20.0 has a spring of force constant k = 500 N/m fastened securely at... Problem 7.64AP: An inclined plane of angle has a spring of force constant k fastened securely at the bottom so that... Problem 7.65AP: (a) Take U = 5 for a system with a particle at position x = 0 and calculate the potential energy of... Problem 7.66CP: A particle of mass m = 1.18 kg is attached between two identical springs on a frictionless,... Problem 7.67CP: Review. A light spring has unstressed length 15.5 cm. It is described by Hookes law with spring... format_list_bulleted