Ques:Answer the following question given this paragraph: Machines make work easier by increasing the amount of force that is applied, increasing the distance over which the force is applied, or changing the direction in which the force is applied. Contrary to popular belief, machines do not increase the amount of work that is done. They just change how the work is done. So if a machine increases the force applied, it must apply the force over a shorter distance. Similarly, if a machine increases the distance over which the force is applied, it must apply less force. Q: If the amount of force of that is applied is increased, what happens to the work that a machine is producing? Choices: - it's unchanged - it is harder - it's variable - it is easier A:

Ans:it is easier
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Ques:Answer the following question given this paragraph: The focal length , , of a lens or mirror is the distance from the surface of the lens or mirror to the place where the light is focused. This is called the focal point or focus . For diverging lenses or mirrors, the focal length is negative. Q: What type of lens and mirrors have a negative focal length? Choices: - converging - convexing - subverging - diverging A:

Ans:diverging
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Ques:Answer the following question given this paragraph: Nuclear energy is produced by splitting the nuclei of radioactive uranium. This doesn't release air pollution or carbon dioxide, but it does produce dangerous radioactive wastes. Q: What type of energy occurs by splitting the nuclei of radioactive uranium? Choices: - microwave - atomic - kinetic - nuclear A:

Ans:nuclear
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Ques:Answer the following question given this paragraph: Kirchhoff's Second Rule Kirchhoff's second rule (the loop rule) is an application of conservation of energy. The loop rule is stated in terms of potential, V , rather than potential energy, but the two are related since PE elec = qV . Recall that emf is the potential difference of a source when no current is flowing. In a closed loop, whatever energy is supplied by emf must be transferred into other forms by devices in the loop, since there are no other ways in which energy can be transferred into or out of the circuit. Figure 21.23 illustrates the changes in potential in a simple series circuit loop. Kirchhoff's second rule requires emf equals the sum of the. Q: Kirchhoff's second rule (the loop rule) is an application of conservation of what? Choices: - heating - Rock - mineral - energy A:

Ans:
energy
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