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    • Thread Starter
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    Please can someone help me to answer this question!!!! Explain to me in detail, by stating the equation used why the answer is C :confused: ...THANKS IN ADVANCE !!!!


    A ball is projected horizontally from the top of a cliff on the surface of the earth with a speed of 40 m/s.Assuming that there is no air resistance, what will its speed be 3 s later?

    A 30 m/s

    B 40 m/s

    C 50 m/s

    D 60 m/s

    E 70 m/s
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    I cant be bothered doing the actual maths to check but horizontal speed will remain constant as there is no air resistance. The ball will accelerate downwards at 9.8m/s^2. You then must essentially use Pythagoras on its vertical and horizontal velocities to find its speed.
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    If there is no air resistance the equation v=u+at can be used. and according to the equation the answer must be 70 and not 50....that's confusing....don't you think equation of motion must be used to find the solution
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    You sound very confused jinx. Why two threads for the same question?
 
 
 
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