Question:
Draw a graph depicting a skydiver’s speed against time when jumping from a plane, until he deploys his parachute, explaining the logic of your answer through the forces applicable to the body.
Methods:
Upon jumping from the plane, the diver experiences three forces; a downward force from his weight; opposed by a lift force (equal to the weight of the air he displaces); and an upward drag force = ½ . (CD.(RHO). V2.A). Initially the largest force is the wight of the jumper, leading an increase in downward velocity due to newtons second law, however, as can be seen from the drag equation, this increase in velocity will lead to a larger increase in drag force, slowing the diver’s acceleration, until the downward forces = the up. At this point the diver is at his terminal velocity. When he releases his parachute, there is again a massive increase in the drag force due to the larger frontal area (A), thereby decelerating the diver until he again reaches a new, reduced, terminal velocity.
Answer:
Upon jumping from the plane, the diver experiences three forces; a downward force from his weight; opposed by a lift force (equal to the weight of the air he displaces); and an upward drag force = ½ . (CD.(RHO). V2.A). Initially the largest force is the wight of the jumper, leading an increase in downward velocity due to newtons second law, however, as can be seen from the drag equation, this increase in velocity will lead to a larger increase in drag force, slowing the diver’s acceleration, until the downward forces = the up. At this point the diver is at his terminal velocity. When he releases his parachute, there is again a massive increase in the drag force due to the larger frontal area (A), thereby decelerating the diver until he again reaches a new, reduced, terminal velocity.
Need extra GCSE Physics Help?
Join our community of students 📝
Every year, 92% our students successfully boost their grades by 2 or more in their core subjects.
