PA04 Legacy question pack

 

Feb 2001

3.         (a)        acceleration proportional to displacement
                        directed to equilibrium position

            (b)        when x= A (the amplitude position)

            (c)        (i)         x0 = amplitude
                        (ii)        1/2mv2(x02 – x2)
                        (iii)      

 

 

 

 

 

 

 

 

4.         (a)        w = 37 x 10-3 m / 29

                        s = l D / w  =  1.24mm

(b)        l decreases from red to green therefore w decreases, fringe width decreases

(c)        no diffraction so no dispersion, colours are not separated

 

6          (a)        you need a 2nd piece of Polaroid
                        rotate it through 90o
                               
see if the light is blocked

            (b)        transverse

 

June2001

2          (a)        (i)         particle motion is perpendicular to wave velocity

                        (ii)        f – same
                                    A – same
                                    phase – 3p/2

                        (iii)       T = 2.5s, sketch position that is p out of phase

            (b)        (i)         reflection has same l as original
                                    equal but opposite velocities

                        (ii)        f – same
                                    A – P is greater than Q

                                    phase – p out of phase

(iii)       sketch has3 nodes along the length of the string – since wavelength is halved.

3.         (a)        vmax = 2pfA      =    0.79ms-1

            (b)        points B & C – where is comes to rest

            (c)       

                       

 

 

 

 

4.         (a)        draw only slight curvature – with same l as incident waves
            (b)        draw semi-circles – again with same l as incident waves
            (c)        diffraction

5.         (a)        (i)         nl - dsinq

                                    d = 1/5 x 105
                                    q  = sin-1(1 x 589 x 10-9 / (1/5 x 105))

                        (ii)        tan17.1 = 0.2 / x
                                    x = 0.2 / tan17.1 = 0.65m

            (b)        n = 2, find q as above then rearrange tanq = d / 0.65 to find d