A planet has a mass of 4.2 x 1024 kg and travels in a nearly circular orbit around a star as shown. When it is at location A, the velocity of the planet is ( 0, 0, -1.8 x 104 ) m/s. When it reaches location B, the planet's velocity is ( -1.8 x 104, 0, 0 ) m/s. We're looking down on the orbit from above, with +x to the right and +z down the page.
(a) What is Δp→, the change in the momentum of the planet between locations A and B?