Terminal velocity

what is weight

the force of gravity on an object

what causes the skydiver to initially accelerate downwards

the force of gravity acting downwards due to the person's mass, they will feel this force as weight

according to galileo in the absence of air resistance all objects fall at a constant acceleration of __

9.8m/s^2

when a skydiver jumps out of a plane what two forces act on them

weight ( due to gravity)

air resistance ( due to friction with air particles)

how does a skydiver reach terminal velocity as they jump out of a plane

1. when the skydiver jumps out they are momentarily stationary in the air

2. however they begin to accelerate downwards due to gravity, due to their mass. We call this force weight

3. as the person accelerates and so their velocity increases, the force of drag acting upwards increases slightly ( when they go faster, they collide with more air particles) . there is still a resultant force acting downwards however it is smaller, and it decreases by the same amount that the drag increased by

4. as the person continues to speed up, the drag continues to increase and eventually grows large enough to balance the downwards weight force

5. once the air resistance equals weight there is no longer any resultant force ( it equals 0), so the skydriver acceleration is zero, so they travel at a constant speed

6. this speed is called their terminal velocity

what are the two factors affecting drag

surface area = the higher the surface area, the larger the area over which collisions can take place

explain how a new terminal velocity is reached when the skydiver opens their parachute

1. when the parachute is opened it drastically increases the surface area, this in turn wil increase the drag as a higher surface area means more collisions with air particles

2. this causes a resultant upwards ( means that they are decelerating downwards/ acclelerate upwards) so they fall slower

3. however as they fall slower the drag will decrease and become equal with the weight again, so the resultant force = 0N and they've reached a new terminal velocity ( however it's lower than the other one)

What is terminal velocity?

the greatest velocity a falling object reaches where the velocity remains constant so no longer accelerating or decelerating