Chapter 6: Q10Q (page 139)

In 1987, as a Halloween stunt, two skydivers passed a pumpkin back and forth between them while they were in free fall just west of Chicago. The stunt was great fun until the last skydiver with the pumpkin opened his parachute. The pumpkin broke free from his grip, plummeted about0.5 km, and ripped through the roof of a house, slammed into the kitchen floor, and splattered all over the newly remodeled kitchen. From the sky diver’s viewpoint and from the pumpkin’s viewpoint, why did the skydiver lose control of the pumpkin?

Short Answer

Expert verified

From the sky diver’s viewpoint, the skydiver loses control of the pumpkin because there is an increase in the apparent weight of the pumpkin.

From the pumpkin’s viewpoint, the diver loses control of it because of sudden net upward force on the diver due to the opening of the parachute.

Step by step solution

The given data

Initially, both the divers were in free fall.
The pumpkin broke free from the grip of the skydiver about 0.5km as he opened his parachute.

Understanding the concept of the relative force

The net forces acting on the pumpkin relative to its viewpoint and the sky diver's viewpoint describe the reason for the fall that differs accordingly, considering the balance in the acting forces for conservation of force.

Calculation for understanding the reason for the pumpkin’s fall

Case-a: From a pumpkin’s viewpoint

Initially both are in free fall. So for skydivers, the apparent weight of a pumpkin is zero. When he opens the parachute, he has net upward acceleration. From the pumpkin's viewpoint, the sudden upward force of the skydiver ripped him upward away from the pumpkin.

Case-b: From the sky diver’s viewpoint

The apparent weight of the pumpkin suddenly increased and the pumpkin was ripped downward from his hands.