1. Warm-up 2/29
Add weight to your formula chart (definition should be in your notes)
A ball has a mass of 1 kilogram. Find its weight in newtons on Earth.
If an object has a mass of 36 kg on Earth, find its mass and find its weight on the moon. (1.6 m/s2)
An object has a mass of 5.5 kilograms. Find its weight in newtons on Earth.

2. Falling and Flying
Chapter 12.2

3. Introduction
When Earth’s gravity is the only force acting on an object, things fall.
And when they fall… they fall fast.
They accelerate at 9.8m/s2 which means that the first second they are falling at 9.8 m/s, then 19.6 m/s, then 29.4 m/s, 39.2 m/s, 49.0m/s, 58.8 m/s, then 68.6 m/s…
If there was no air resistance, we would keep accelerating until we hit the Earth.

4. Free Fall
Free Fall occurs when only the force of gravity is acting on an object.
In the absence of air resistance, all objects falling near Earth’s surface accelerate at the same rate regardless of their mass.
This is due to Newton’s second law. F a __ __ F a =
Free Fall physics
skydiving physics

5. Free Fall
When we fall, there are two forces acting on us: air resistance and gravity.
Because we have an atmosphere filled with air, we will be slowed down by the molecules in the air.
Ffric
Fgrav

6. Free Fall
A falling object stops accelerating when the force of air resistance is equal to the force of gravity (weight).
At this point an object reaches its maximum falling velocity – known as terminal velocity.
Terminal velocity through Earth’s atmosphere is about 320 km/h (200 mi/h)

7. Free Fall If we increase air resistance our bodies will slow down.
Wingsuit base jumping
If we increase air resistance our bodies will slow down.
Opening a parachute decreases terminal velocity to a safe speed.

8. Free Fall
We can even manipulate upward air resistance to give us lift and help us fly.
Lift is an upward force on an object within a fluid.
Lift is generated when an object (like a plane) controls the directional flow of a fluid around its body.
As the plane directs air flow down, the air pushes the plane up.

9. Projectile Motion
Ok.. So now we understand what happens when we fall, but what happens when we throw an object?
The curved path an object takes when it is thrown or launched is called projectile motion.

10. Projectile Motion Projectile motion consists of two components:
The horizontal component is the applied force on the object.
The vertical component is the force of gravity.
When the two combined forces act on the object, it will follow a curved path.

11. Because the vertical force of gravity is causing your arrow to be pulled downward, you must aim higher than the target.