How fast does a tandem skydive go?

Answer 1

The velocity of a skydiver is largely governed by weightand drag. Obviously both can vary quite a bit. The typical skydiver flying in "belly" or prone position reaches the terminal velocity of about 110mph to 130mph (typically 120mph) after about 1000ft of freefall. This equates to a rate of approximately 1000ft for every 5.5 seconds. Tandems would fall at 150 to 180 mph if it wasn't for a drogue chute that is deployed by the tandem instructor shortly after leaving the aircraft to increase the drag on the tandem pair. This is needed because there is about twice the weight and essentially the same drag because the student is laying directly below the instructor. If you double the weight without increasing the surface area the fall rate will increase by a factor of the square root of 2. So, about 170 mph for an average tandem pair with no drogue. Similarly to the situation with an individual skydiver, tandem freefall rates can vary quite a bit. Many camera fliers wear small wings under their arms to allow them a higher range of adjustability in their fall rates.

Answer 2

The velocity of a skydiver is largely governed by weightand drag. Obviously both can vary quite a bit. The typical skydiver flying in "belly" or prone position reaches the terminal velocity of about 110mph to 150mph (typically 130mph) after about 1000ft of freefall. This equates to a rate of approximately 1000ft for every 5.5 seconds. Tandems would fall at about twice that velocity if it wasn't for a drogue chute that is deployed by the tandem instructor shortly after leaving the aircraft to increase the drag on the tandem pair. This is needed because there is about twice the weight and essentially the same drag because the student is laying directly below the instructor. Similarly to the situation with an individual skydiver, tandem freefall rates can vary quite a bit. Many camera fliers wear small wings under their arms to allow them a higher range of adjustability in their fall rates.

The rate of change of velocity "g" caused by earths gravity is a constant in a vacuum. But we have variables such as air resistance which may change due to change in air density and the surface area of an object falling through the air.

Skydivers utilize that principle through adjustments in body position, using baggy jumpsuits to increase drag, streamline jumpsuits to reduce it, wings as mentioned previously and lead shot to increase weight.

At the start of the freefall, gravity "g" is the overwhelming force as the low velocity produces minimal drag but as the velocity increases due to the acceleration g then so does drag and the rate of acceleration reduces to the point where it reaches zero. This is the so called terminal velocity and is the point where the force g and the drag are equal and opposite forces. Now the fun begins.

Because forces on a skydiver are in constant flux due to intentional or unintentional changes in body attitude (position) and changes in air density due to air temperature changes and altitude, the net force on a skydiver may approximate zero but there is always some out of balance force somewhere. Even gravity changes as we approach the ground, but by an infinitesimal amount. Even mass m is affected by v velocity. Unless you were skydiving at a reasonable factor of the speed of light, this may be ignored.

Ever tried to balance a knife on its edge ?