posted by Anonymous .
A helicopter lifts a 70 kg astronaut 13 m vertically from the ocean by means of a cable. The acceleration of the astronaut is g/10.
(a) How much work is done on the astronaut by the force from the helicopter? J
(b) How much work is done on the astronaut by her weight? J
(c)What is the kinetic energy? J
(d) What is the speed of the astronaut just before she reaches the helicopter? m/s
Start with calculating the final velocity v (upwards) of the astronaut (m=70 kg) who starts from rest (v0=0) subject to an acceleration of a=0.1g and through a distance of H=13m.
solve for v.
a. sum potential and kinetic energies
potential energy gain, Ep = mgH
kinetic energy gain, Ek = (1/2)mv²
Work done = Ep + Ek