Acave rescue team lifts an injured spelunker directly upward and out of a sinkhole by means of a motor-driven cable. the lift is performed in three stages, each requiring a vertical distance of 11.0 m: (a) the initially stationary spelunker is accelerated to a speed of 1.10 m/s; (b) he is then lifted at the constant speed of 1.10 m/s; (c) finally he is decelerated to zero speed. how much work is done on the 78.0 kg rescue by the force lifting him during each stage?

Answer

Mass m = 78 kg

Vertical height in each stage h = 11 m

(a).

Initial speed u = 0

Final speed v = 1.1 m / s

a = 0.055 m/s²

Work done

(b).Work done

W_b = 78× 9.8× 11

c)

Work done

Where V = final speed

               = 0

            v = 1.1 m / s

for deceleration a = -0.055 m/s²

now,

W_c = 545.75 × 11

molecules are free to separate from each other and will take on the shape of the container. molecules move completely at random and high speeds. they vibrate in a fixed position and do not move around much. molecules expand to the edge of their container.