A ball falls from a height h from a tower. Which of the following statements is true?
(A) The potential energy of the ball is conserved as it falls.
(B) The kinetic energy of the ball is conserved as it falls.
(C) The difference between the potential energy and kinetic energy is a constant as the ball falls.
(D) The sum of the kinetic and potential energies of the ball is a constant.
(E) The velocity of the ball is constant as the ball falls.
Ans: (D) The sum of the kinetic and potential energies of the ball is a constant.
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The direction of an electric field is from higher to lower potential
Indicate whether the statement is true or false
A coil is rotated in a magnetic field generating an emf given by emf = NBA? sin ?, where ? = ?t. At which angle ? is the emf one-third of its maximum value?
a. 0° b. 19.5° c. 6.4° d. 70.5° e. 60.0º
Jadeen says that you can increase the resistance of a copper wire by hammering the wire to make it narrower and longer. Arnell says that you can increase its resistance by heating the wire. Which one, if either, is correct, and why?
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A disk and a hoop of the same mass and radius are released at the same time at the top of an inclined plane. Which object reaches the bottom of the incline first?
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