Física

Section: 7-1 Topic: The Conservation of Mechanical Energy Type: Conceptual 1. The total mechanical energy of any system is A) always the work done by gravity. B) the difference between the kinetic and potential energy at any point. C) the sum of the kinetic and potential energy at any point. D) the sum of the translational and rotational kinetic energies at any point. E) the potential energy of a spring at any displacement.

Section: 7-1 Topic: The Conservation of Mechanical Energy Type: Conceptual 2. A body falls through the atmosphere (consider air resistance) gaining 20 J of kinetic energy. How much gravitational potential energy did it lose? A) 20 J B) more than 20 J C) less than 20 J D) It is impossible to tell without knowing the mass of the body. E) It is impossible to tell without knowing how far the body falls.

Section: 7-1 Topic: The Conservation of Mechanical Energy Type: Numerical 3. A projectile of mass m is propelled from ground level with kinetic energy of 450 J. At the exact top of its trajectory, its kinetic energy is 250 J. To what height above the starting point does the projectile rise? A) B) C) D) E)

Section: 7-1 Topic: The Conservation of Mechanical Energy Type: Conceptual 4. A block of mass m is pushed up against a spring, compressing it a distance x, and is then released. The spring projects the block along a frictionless horizontal surface, giving the block a speed v. The same spring projects a second block of mass 4m, giving it a speed 3v. What distance was the spring compressed in the second case? A) x B) 2x C) 3x D) 4x E) 6x

Section: 7-1 Topic: The Conservation of Mechanical Energy Type: Conceptual 5. Release mass m on a string from rest at point A. As it passes the lowest point B, the tension in the string is A) impossible to determine; the answer depends on