Question

The space probe Deep Space 1 was launched October 24, 1998, and it used a type of engine called an ion propulsion drive. Suppose the probe, which has a mass of 474 kg, is traveling at an initial speed of 275 m/s. No forces act on it except the 5.6×10^-2 N thrust of its engine. This external force is directed parallel to the displacement, which has a magnitude of 2.42×10⁹ m (see figure). Determine the final speed of the probe, assuming that its mass remains nearly constant.

A. 555 m/s

B. 645 m/s

C. 805 m/s

D. 755 m/s

Answer 1

Correct Option: C. 805m/s

Mass of the probe m=474kg

Initial speed of the probe v_i=275m/s

Force acting on the probe

Displacement of the probe

The force is parallel to displacement, the angle between the force and the displacement is

The work done by the force is

By Work-energy theorem, net work done on the probe is equal to the change in kinetic energy of the probe.

Substituting values