Halliday, Resnick & Walker — Motion in Two and Three Dimensions: Problem 78

78 In the overhead view of Fig. 4-38, Jeeps P and B race along straight lines, across flat terrain, and past stationary border guard A. Relative to the guard, B travels at a constant speed of \(25.0 \text{ m/s}\), at the angle \(\theta_2 = 30.0^\circ\). Relative to the guard, P has accelerated from rest at a constant rate of \(0.400 \text{ m/s}^2\) at the angle \(\theta_1 = 60.0^\circ\). At a certain time during the acceleration, P has a speed of \(40.0 \text{ m/s}\). At that time, what are the (a) magnitude and (b) direction of the velocity of P relative to B and the (c) magnitude and (d) direction of the acceleration of P relative to B?