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Please help me I need to get this done

  1. Nov 8, 2009 #1
    please help me I need to get this done!!!

    I have a this big assignment to get in, in not a big portion of my grade but I'll still get 2 days detention if I don't get it in, and I have to go to an important meeting tomorrow. This teacher is noted as being one of the worst at my school, she's totally incompetent, and no one likes her teaching methodes. To put it simply I LOVE Science and usually have a 96% or higher, this is the ONLY semester I have NOT...tell me there isn't a connection..! anyway here are the questions I CAN'T answer, since I have to have it in by midnight can someone PLEASE help me, I'm losing my mind!!!!!



    (1.) Calculate the Mass.
    PE = 1250J
    Height = 6m
    velocity = 2m/s

    Possible Answers:
    208.3kg
    21.3kg
    73500kg
    or
    21.3 g
    ______________________________________…

    (2.) KE = 3000J
    velocity = 8 m/s

    Possible Answers:
    96000 kg
    187.5 kg
    46.9kg
    93.8kg
    ______________________________________…

    (3.) Calculate the kinetic energy if an object that has a mass of 6kg is moving 3m/s2.

    Possible Answer:
    9J
    18J
    27J
    27kJ
    ________________________________________…

    (4.) Using the f=ma and w=fd formulas, calculate work if:

    mass = 20kg

    acceleration = 3m/s2

    distance = 40m

    Possible Answers:
    1.5 J
    2400N
    2400J
    240 J
    ________________________________________…

    (5.) _________ describes potential energy.

    Possible Answers:
    stored energy
    m/s2
    mass times acceleration due to gravity
    energy in motion
    ________________________________________…
    (6.) How much work was done during the 1000m of the race?

    Given Information:

    During a bicycle race, a cyclist who had a mass of 50kg used a bike with a mass of 20kg. As he began the race, he was able to displace 100m the first 10sec of the race. As the race continued, his velocity increased to 25m/s at exactly 20sec of the race. He was able to maintain this acceleration for a total of 1000m.
    Possible Answers
    1050kJ
    70000J
    75000J
    1500J
    1500N
    105000J
    ________________________________________…
    (7.) What is the mass of a golfball that has a momentum of 1 kg*m/s and is moving 25m/s?
    0.04kg
    100 kg
    25 kg
    0.04 kg*m/s
    ______________________________________…
    (8.) ______________ describes kinetic energy.

    Possible Answers:

    energy in motion
    stored energy
    mass x acceleration due to gravity x height
    Newton
    ________________________________________…
    (9.) What unit describes work?
    Possible Answers:
    m/s2
    N-m/s
    J
    kg *m2/s
    ________________________________________…
    (10.) What is the total energy of a system that has 4000 J of potential energy and 1000 J of kinetic energy?
    Possible Answer:
    3000J
    4 kJ
    4000000 J
    5000J
    ________________________________________…
    (11.) Calculate power if it takes 60seconds to complete 30J of work.
    Possible Answers:
    2 W
    0.5 W
    1800 W
    0.5 J
    ________________________________________…
    (12.) Another way to describe a Newton is
    Possible Answers:
    kg*m*s
    kg*m/s
    m/s2
    kg*m/s2
    ________________________________________…
    (13.) Calculate distance if

    work = 300J

    and force = 3N
    Possible Answers:
    100m
    10m
    900m
    10J
    ________________________________________…
    (14.) What is the potential energy of a 0.5kg grapefruit just before it is dropped off a building rooftop that is 150m in height?
    Possible Answers:
    75 J
    11250J
    735 J
    367.5 J
    ________________________________________…
    (15.) What unit describes force?
    Possible Answers:
    Newton
    joule
    N-m
    N-m2
    ________________________________________…
    (16.) Calculate power if a it took a force of 30N to push a car a distance of 20m. The time it took to move the car 20 m was 0.5min.
    Possible Answers:
    20W
    120 W
    1200 W
    1W
    ________________________________________…
    (17.) Given Information:

    During a bicycle race, a cyclist who had a mass of 50kg used a bike with a mass of 20kg. As he began the race, he was able to displace 100m the first 10sec of the race. As the race continued, his velocity increased to 25m/s at exactly 20sec of the race. He was able to maintain this acceleration for a total of 1000m.

    If the cyclist hit a car at exactly 20secof the race, what force would he exert on the car?
    Possible Answers:
    105N
    1250N
    700N
    75N
    70kg
    ________________________________________…
    (18.) What is the height of a tree if a 0.1kg apple has 20J of potential energy just before it falls to the ground?
    Possible Answers:
    20.4m
    200m
    40.8m
    2.0m
    ________________________________________…
    (19.) How long does it take to perform 100J of work with a power rating of 20W?
    Possible Answers:
    5 W
    2000 W
    5s
    0.5 s
    ________________________________________…
    (20.)What is the mass of an object that has 450J of kinetic energy and is moving at 30m/s?
    Possible Answers:
    15kg
    1kg
    30kg
    0.5 kg
    ______________________________________…
    (21.) Use the given information to calculate velocity:

    mass = 60kg

    PE = 3000 J

    KE = 4000J
    Possible Answers:
    11.5m/s
    89.4m/s
    10m/s
    133.3 m/s
    ______________________________________…
    (22.) The final unit when calculating kinetic energy is _______.
    Possible Answers:
    Newton
    kW
    Joules
    watt
    ________________________________________…
    (23.) USe the given information to calculate potential energy:

    mass = 50kg

    velocity = 3m/s

    height = 4m
    Possible Answer:
    1960J
    5880J
    600J
    225J
    ________________________________________…
    (24.) Calculate work if :

    f= 30N and distance = 3000m
    Possible Answers:
    90000J
    100J
    9000J
    90000N
    ______________________________________…
    (25.) Calculate time if:

    force = 25N

    distance = 1000cm

    power rating = 5W
    Possible Answers:
    5000s
    500s
    5 min
    50s








    Sorry There's so many, This isn't all of them F.Y.I. so I wasn't just like "hey man do this all for me." There's 57 questions, these are just the one's that I can't do. Please help me out! I have a spliting headache and I am EXTREMELY stressed out. Thank you!!!!!!
    1. The problem statement, all variables and given/known data



    2. Relevant equations



    3. The attempt at a solution
     
  2. jcsd
  3. Nov 8, 2009 #2
    Re: please help me I need to get this done!!!

    I'm sorry, but to be blunt, I don't see how you can't answer questions like the one's I quote below, or rather be completely stuck on them, if you maintain a 96% in the sciences.

    I hope your headache feels better, but you're going to have to show some attempt at the problems before people will help you here.

     
  4. Nov 8, 2009 #3

    Vanadium 50

    User Avatar
    Staff Emeritus
    Science Advisor
    Education Advisor

    Re: please help me I need to get this done!!!

    I'm sorry that you have a headache, but, asking us for the answers to 25 out of 57 problems without an attempt at a solution is moving beyond the realm of "homework help" and into the realm of "doing homework for you".
     
  5. Nov 8, 2009 #4
    Re: please help me I need to get this done!!!

    The methods to solve most of those are the first thing that a person would find by looking up the vocabulary words in the index of a book.
     
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