AP Review: Motion in Two Dimensions

AP Review - Motion in Two Dimensions

Quick Review: Gravitational Force and Inclined Planes

• The center of gravity is the point at which the entire weight of a body may be considered to be concentrated.

• Normal Force is the force keeping an object from falling through a surface. The normal force is always perpendicular to the surface.

Multiple Choice

Force of gravity is directly proportional to

• Mass

• Weight

• Distance

• Time

Multiple Choice

Is it possible for the normal force to be equal to the gravitational force?

• Yes. If the surface is horizontal.

• Yes. If the surface is vertical

• No. FN will always be less than Fg

• No. Fg will be less than FN.

Multiple Choice

As the angle of the incline increases, what happens to the normal force?

• The normal force increases

• The normal force decreases

• The normal force is not affected by the incline

• The normal force is only dependent on the force due to gravity

Horizontal Projectile Motion

• Objects that are launched into the air are called projectiles. The path followed by a projectile in motion is called a trajectory.

• A force is not required to keep an object in motion.

• Motion in the X and Y dimensions are independent of each other.

Multiple Choice

In a projectile motion we always have...

• 1 component (x)

• 3 components (x,y, and z)

• 2 components (x and y)

• 0 components

Multiple Choice

The more mass an object has, the faster it will fall.

• True

• False

Multiple Choice

An object is projected horizontally from a cliff.  The time it takes to hit the ground is

• more than if it was just dropped
• less than if it was just dropped
• the same amount of time than if it was just dropped
• impossible to determine

Multiple Choice

What is the vertical acceleration of a projectile?

• 0 m/s²

• 9.8 m/s²

Multiple Choice

What is the horizontal acceleration of a projectile?

• 0 m/s²
• 9.8 m/s²

Angled Projectile Motion

• Gravity is a vertical force, the only one that acts on a projectile.

• Projectiles follow a parabolic trajectory once launched.

• In Angled Launched, the object is projected up and horizontally at the same time.

• Angle affects height and range.

Multiple Choice

In the absense of air resistance, as an object travels through the air, its horizontal velocity

• changes

• remains the same

Multiple Choice

A ball is thrown into the air at some angle. At the very top of the ball's path, its velocity is

• entirely vertical

• both vertical and horizontal

• entirely horizontal

• not enough info

Multiple Choice

In the absence of air resistance, the angle at which a thrown ball will go the farthest is

• 15^o
• 30⁰
• 45^o
• 60⁰