ANSWERS: 1
  • There are two types of energy described here: gravitational potential and kinetic energy. Gravitation potential is given by mgh, where m is mass, g is gravity (9.8 m/s2 in this case) and h is height. These are all given, so just multiply the numbers. Kinetic energy is given by 1/2 mv2, where m is mass and v2 is velocity squared, so, square the given velocity, multiply it by the mass and divide by two (or multiply by one half, same thing). Then, add the two energy values together and you should get the correct answer. Let's try: Eg = mgh = 5 kg 9.8 m/s2 10 m = 4900 J (1 J = 1 kg m/s2). Ek = 1/2 mv2 = 1/2 5 kg (20 m/s)^2 = 1000 J. Etot = Eg + Ek = 4900 J + 1000 J = 5900 J.
    • Linda Joy
      You've given them the wrong answser. You need to re-read the question. And I think they do too, because they probably copied it wrong in the question. Two common mistakes in math/physics. Evidently they are on some planet that has a different gravitational force than 9..8 m/s^2 because he specifically stated "take acceleration due to gravity as 10m/s" (Which I'm thinking is probably actually seconds squared in the original question rounded up for simplicity) And a good lesson as to why they should go to a homework help site instead of coming here where some people (not you) will give them the wrong answer on purpose just to teach them to do their own homework. I would suggest you google "free homework help site."

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