A small robotic probe is drifting in deep space far from significant gravitational fields. At t = 0 the probe’s velocity relative to a fixed origin is v0=(250i^+400j^)m/s. An onboard thruster then fires for exactly 20 s, exerting a constant force that adds an additional Δv=(30i^−20j^)m/s to the probe’s velocity. Immediately after the thruster shuts off (t = 20 s) no further forces act on the probe.
(a) Determine the probe’s velocity vector at t = 20 s.
(b) For the interval from t = 20 s to t = 260 s, calculate the probe’s position vector relative to its position at t = 20 s.
(c) State whether the net force acting on the probe is zero during the interval described in part (b) and justify your answer using appropriate physical reasoning.