Simple Formulas
Fill In The Blank (g=10m/s/s)
Skydiving (by stepping gently off of a very high platform)
Forces with Simple? Kinematics
Net force as The Vector Sum of Individual Forces
100

Net force

ma

100

3kg

100

These are all of the forces acting on a falling skydiver.

Weight and drag

100

The tension in a rope that is raising a 60kg boat crash survivor with an upward acceleration of 1m/s/s.

[assume g=10m/s/s]

660N

100

T1-w1

200

Weight

mg

200

3m/s2

200

This describes the situation of an object that is falling through the air but not accelerating.

Terminal Velocity

200

If a 10 kg running child has a velocity of 5m/s one second after having a velocity of 3m/s, this is the horizontal force that the floor is exerting on the child.

20N

200

300

Friction

300

60N

300

The correct comparison of a skydiver's drag force at terminal velocity with a closed chute closed, versus the same skydiver's drag force at terminal velocity with the chute open. (Stronger, weaker, or the same)

Same

300

The weight of a 50kg person whose velocity is 8m/s after falling for 4 seconds on a strange planet.

100N

300

400

Tension in a string supporting a weight of mass m with acceleration a.

m(g+a)

400

0.6

400

The only point at which a skydiver is truly in freefall.

The beginning

400

The force required to constantly accelerate a 2kg block from rest over a distance of 12m, in 2 seconds.

12N

400



T2-w3

500

Reading of a scale that is supporting a mass m in an elevator when the mass m has an acceleration a.

m(g+a)

500

20N

500

The usual number of times Y acceleration enters positive territory during a skydive.

2

500

The approximate force of drag acting on a 100kg skydiver while descending 600m over a time of 200s, and then falling 1,200m over a time of 400s, and next further continuing to descend of 900m over the next 300s.

[assume g=10m/s/s]

1,000N

500