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## Work and also Energy Review

Navigate to:Recheck out Session Home - Topic Listing**Work and Energy - Home || Printable Version || Questions through LinksAnswers to Questions: All||#1-10||#11-25||#26-36||#37-45**

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**Part A: Forced Choice Questions**

1. Which of the adhering to statements are true around work? Include all that apply.

You watching: Which of the following statements is true of group tasks?

a. b. c. d. e. f. g. h. i. j. k. l. m. n. o. |

Useful Net Links |

Definition and also Mathematics of Work |

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2. Which of the following statements are true around power? Include all that use.

Power is a time-based amount.Power describes exactly how quick work is done upon a things.Powerful people or effective equipments are ssuggest human being or machines which always perform most work-related.A force is exerted on an object to move it at a constant speed. The power ceded by this pressure is the magnitude of the force multiplied by the speed of the object.The standard metric unit of power is the Watt.If perboy A and perchild B perform the same task yet perchild B does it faster, then perboy A does more occupational yet perchild B has actually even more power.The Newton•meter is a unit of power.A 60-kg boy runs up a 2.0 meter stairsituation in 1.5 seconds. His power is about 80 Watt.A 300-Newton force is used to a skier to drag her up a ski hill at a constant speed of 1.5 m/s. The power ceded by the toe rope is 450 Watts.Answer: ABDEI a. b. c. d. e. f. g. h. i. |

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Power |

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**3. Consider the complying with physical instances. For each case, identify the angle between the shown force (in boldface type**) and also the displacement ("theta" in the work-related equation).

a. 0 degrees | b. 180 degrees | c. 90 degrees | d. 30 degrees | e. 60 degrees |

**used force**is provided to dislocation a television set to the best. -

**Answer: A - 0 degrees**The

**force of friction**acts upon a rightward-relocating auto to carry it to a sheight. -

**Answer: B - 180 degrees**A waiter uses an

**used force**to balance the weight of a tray of plates as he carries the tray throughout the room. -

**Answer: C - 90 degrees**The pressure of

**air resistance**acts upon a vertically-falling skydiver. -

**Answer: B - 180 degrees**The

**pressure of friction**acts upon a basesphere player as he slides right into third base. -

**Answer: B - 180 degrees**An

**used force**is provided by a freshmale to lift a World Civilization book to the peak shelf of his locker. -

**Answer: A - 0 degrees**A bucket of water is tied to a string and also

**tension**offers the centripetal pressure to save it moving in a circle at continuous rate. -

**Answer: C - 90 degrees**An

**applied force**acting at 30-degrees to the horizontal is supplied to disarea an item to the ideal. -

**Answer: D - 30 degrees**A team of footround players use an

**used force**to press a sled across the grass. -

**Answer: A - 0 degrees**The

**tension**in the elevator cable causes the elevator to increase at a continuous rate. -

**Answer: A - 0 degrees**In a physics lab, an

**applied force**is exerted parallel to a airplane inclined at 30-degrees in order to disarea a cart up the incline. -

**Answer: A - 0 degrees**An

**applied force**is exerted upwards and also rightwards at an angle of 30-levels to the vertical in order to dislocation a things to the right. -

**Answer: E - 60 degrees**A child rests on the seat of a swing which is supported by the

**tension**in its cables; he swings from the highest possible position to its lowest position. -

**Answer: C - 90 degrees**

a. The forward motion is do to the forward pushing; if the force and also motion are in the very same direction, then the angle is 0 degrees. b. Friction opposes motion and also as such does negative work; the angle is 180 degrees. c. The pressure is vertical and the displacement if horizontal; they make a 90 level angle. d. Air resistance opposes activity and also as such does negative work; the angle is 180 levels. e. Friction opposes activity and as such does negative work; the angle is 180 levels. f. The frosh applies an upward force to cause an upward displacement; the angle is 0 degrees. g. For unidevelop circular activity, the pressure is inwards and the displacement at each instant is tangent to the circle; these two vectors make a 90 degree angle. h. This is a straightforward question; no tricks here. i. The forward motion is do to the forward pushing; if the pressure and also activity are in the exact same direction, then the angle is 0 levels. j. The cable pulls up on the elevator and also the elevator is disput upward; if the force and also activity are in the very same direction, then the angle is 0 levels. k. The 30-level angle is the incline angle, not necessarily the angle between F and d. The pressure is parallel to the incline and also the cart is disput along the direction of the incline; so the 2 vectors are in the exact same direction and the angle between them is 0 levels. l. Compare the wording of this to part h. This one is tricky because the angle between F and also d is 60-levels. If you missed it, rereview the question, paying mindful attention to the "with the vertical" component. m. As the boy swings, she traces out a circular arc and also as such the stress and anxiety (centripetal) is perpendicular to the direction of motion (tangent). |