The lockheed sr-71 blackbird aircraft made an absolute speed record in 1976. calculate the aircraft's top speed in kilometers per hour if its flight was characterized by the mach angle a 17.8 degrees. the speed of sound at the flight altitude is 300 m/s. [10 marks] (b) light can be viewed as an electromagnetic wave or as a particle with momentum punk where = h/21 = 1.055 x 10- js and k is the photon wave number defined as k = 2/1 the speed of light in vacuum is c = 3 x 10 m -. determine whether the propagation of a photo in vacuum is dispersive by calculating both phase and group velocities for propagation of light in vacuum. [20 marks) (c) (i) formulate the equation of motion for a damped oscillator driven by a sinusoidal driving force f(t) = fosin wt. the damping force is given by-bv where v is the velocity and b is the viscous force constant. (i) find the expression for the steady state amplitude a and phase shift 8 of the oscillations as a function of the driving frequency w, and (iii) find the value of the steady state amplitude for the system characterized by the mass m = 0.5 kg, the spring constant k = 200 n/m, the viscous force constant b 10 n s/m, and the amplitude and angular frequency of the driving force fo=20 n and w = 30 rad/s respectively.