Question

4. Space Junk (8 points) A satellite, with a mass of 60 kg, is traveling at a velocity vs = 75 m/s in the x direction, as shown in the figure below. It is struck by a wrench, with a mass of 3 kg, accidentally dropped by an astronaut, which is moving at a velocity Vw -170 m/s in the negative y direction. The collision is completely inelastic. (a) (2 points) Before the collision, what is the wrench's kinetic energy? (b) (2 points) Before the collision, what is the wrench's momentum? (c) (4 points) After the collision, what is the satellite's velocity? (Give your answer in terms of x and y components.)

Answer 1

a) Kinetic energy of wrench = 1/2 mv^2 = 1/2 times 3 times 170^2 = 43350 Joule b) wrench's momentum = m times v = 3 times 170 = 510 N - sec c) m_s = 60 kg v_s = 75 m/s rightarrow g_n n -direction m_s times v_sn + m_w times v_wn = (m_s + m_w) v_x Righatrrow 60 times 75 + 3 times 0 = (60 + 3) v_n Righatrrow v_n = 71.03 m/s rightarrow In y - direction m_s times v_sy + m_w times v_wy = (m_s + m_w) times v_g Rightarrow 60 times 0 + 3 times (-170) = 63 times v_y Righatrrow v_y = -8.09 m/s -ve sign implies -ve y - direction