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    Best location for a light bulb filament using a concave mirror?

    Where is the best location for a light bulb filament to be placed in a spotlight, when using a concave mirror? It makes the most sense to put it at the focal point of the mirror if you want parallel light beams but are you supposed to have parallel light beams when you use a spotlight? Or do...
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    Pendulum bob must circle rod

    The pendulum bob in the above figure must circle the rod interrupting its swing, and the string must remain taut at the top of the swing. How far up must the bob be raised before releasing it to accomplish these goals? I don't know where to begin with this because I don't quite understand...
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    Calculating net force, simple question.

    I'm trying to calculate the acceleration of an object but first I need to calculate the net force. For this question we were told Fnet = Fa-Fd-Ff.. just wondering what Fd is? Thank you in advance.
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    How to use a spring balance in space?

    A spring balance cannot be used to measure the weight of anything under the conditions of a space shuttle. Is there any way you might use a spring balance to compare the 'heaviness' of twin babies born on the shuttle? Discuss. I don't know how you'd use a spring balance in the shuttle.. Any...
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    Forces on angles

    Two horses on opposite sides of a narrow stream are pulling a barge along the stream. Each horse pulls with a force of 720N. The ropes from the horses meet at a common point on the front of the barge. What is the resultant force exerted by the two horses if the angle between the rope is 60o...
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    Acceleration on a ramp with coefficient of friction

    What is the acceleration of a 25kg block sliding down a ramp at 30 degrees to the horizontal, if the coefficient of friction is 0.3? ans= 2.4m/s2 I haven't done this in a while.. I can't remember how to apply the coefficient of friction.. Thank you! PLEASE DISREGARD.. I've figured...
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    Type 1 Projectile with an initial vertical velocity

    A rude tourist throws a peach pit horizontally with a 7.0 m/s velocity out of an elevator cage. The ground is 17 m below. How long will it take for the pit to land if the elevator is moving upward at a constant 8.5 m/s velocity? d=Vot + 1/2at2 My attempt that continuously doesn't...