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    Simple vector physics-please help!

    Simple vector physics--please help! I'm having a little trouble with this physics problem. It seems so simple but I am stumped. A river flows with a uniform velocity v. A person in a motorboat travels 0.942 km up- stream, at which time a log is seen floating by. The person continues to...
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    What is the theoretical minimum force

    a 82.500 kg student, starts from rest. A constant force acts on him for 37.5m to give him a speed of 97.5 m/s. Use the Work- energy theorem to find the magnitude of the force. this is my equation which I'm unsure about 1. f*s= .5mv^2f - .5mv^2i 2. f= .5(82.5)(97.5^2)/37.5 I just want to...
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    Another conservation of momentum

    The issue of the New York Times had a mass of 5.4 kg. Suppose a skateboarder picks up a copy of this issue to have a look at the comic pages while rolling backward on the sakteboard. Upon realizing that the New York Times doesn't have a "funnies" section, the skateboarder promptly throws the...
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    Conservation of momentum problems

    The larges grand piano in the world is really grand. Built in London, it has a mass of 1250 kg. Suppose a pianist finishes playing this piano and pushes herself from the piano so that she rolls backwards with a speed of 1.4m/s. Meanwhile, the piano rolls forward so that in 4.0s it travels 24 cm...
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    Tension in the coupling between the locomotive and the first car

    A 97 250kg train pulls two freight cars. The first car has a mass of 51 355 kg and the second has a mass of 18 400 kg. The whole train accelerates at .01750m/s^2. What is the tension in the coupling between the locomotive and the first car? A. I used Ft=ma and took (51355)(.1750)= 8987.1 N...
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    Why more matter than antimatter

    If there is duality, at the big bang, when matter and antimatter was created, why did the balance shift to matter? Someone told me that there is a theory that the particles that have no charge was left over and created matter?
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    Help with problems over Newton's Laws

    I need help with these problems that I'm not quite sure on how to do, I have attempted and gotten and answer, but I tend to be wrong... 1. a 0.095 KG pom pom slides along the gym flour with an initial speed of 5.50 m/s. It came to a complete stop in 1.9 m. What is the coefficient of...