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    These are the questions below. Basically what i am having trouble with is:
    finding time between collisions given force initial speed and colision speed.

    how to find maximum range of projectile from height of y0 and optimum angle

    for a planet in orbit, at particular time it has r=a and speed=u. what would be energy and angular momentum and what would happen if: u<1, u>1 and u=1/a

    thanks!
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    1. Train A is moving with speed v_i and sees train B stationary ahead. He puts his brakes on to avoid a collisionand isslowed by force deltaMv where v is speed and M is mass of train A. But train A hits train B with speed v_f. Find the time T between application of brakes and collision.

    2a. A man climbs on a mountain of height y_0. The stone is thrown at an angle of 0 to the horizontal . r(t)=x(t)i+y(t)j find x(t) and y(t) and hence trajectory y(x).
    b.how far is it thrown if thrown horizontally?
    c. Roughly what is the best angle in order to throw the stone as far as possible assuming geight y0 is much larger than max height boy can throw. explain answer briefly?

    3a. A planet moves with position r and central force F(r). Derive a formula for velocity in suitable polar coordinates and so write L=lLl and planets KE.
    b. if F(r)=-1/r^3 find a formula for total energy E.
    c. if r=a then the planets sped u is transverse to position, then express E and L in terms of a and u and so relate dr/dt to r and these constants.
    d. describe the motion in cases: u<1, u>1 and u=1/a


    thanks!
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    ???
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    (Original post by number23)
    ???
    You've been posting long enough to be aware of the forum guidelines.

    Just posting a mass of questions isn't going dispose people to just do them for you. You need to say what problem you're having, what have you been able to do, etc.
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    (Original post by ghostwalker)
    You've been posting long enough to be aware of the forum guidelines.

    Just posting a mass of questions isn't going dispose people to just do them for you. You need to say what problem you're having, what have you been able to do, etc.
    ok thnx ive edited my post
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    (Original post by number23)
    ok thnx ive edited my post
    For your first one. Apply F=ma, and note that a is dv/dt.

    You now have a very simple differential equation.
 
 
 
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