1. Bellringer
Answer the following two questions in complete sentences.
1. What type of friction does a heavy box being pushed across the floor experience?
Sliding Friction
2. Compared to the motion of the box, what is the direction of the force of friction?
Friction acts in the opposite direction of an object’smotion.

2. Friction on a Falling Object
Gravity!
Why do objects fall?
Gravity- the force that pulls objects towards each other.
On Earth, objects are attracted towards Earth.

3. What if gravity was the only force acting on a falling object?
Free fall- the motion of a falling object when
the only force acting on it is gravity.
Objects in free fall accelerate as they fall.
They accelerate due to gravity at a rate of 10 m/s2 (9.8 m/s2).

4. On Earth there is a force that acts upon falling objects.
Air resistance- the fluid friction experienced by objects through air.
The larger the surface area that an object has, the greater the air resistance.
Air resistance increases with greater velocity.

5. Terminal velocity- the maximum velocity of a falling object achieves.
Occurs when air resistance equals the force of gravity. There is no acceleration because it is a balanced force.
Differs for each object depending on how compact (dense) the object is.

6. Monkey & Hunter (Projectile Motion)
Projectile- an object that is thrown.
* Thrown horizontally
* A project will reach the ground at the same time of a dropped object.
Monkey & Hunter (Projectile Motion)