PROJECTILE MOTION

Chapter 3

Scalar and Vector Quantities

■ In describing motion we’ll use two different quantities.– Scalars have a single attribute, a magnitude.

■ Examples: distance, speed, time, temperature

– Vectors have two attributes, a magnitude and a direction.■ Examples: displacement, velocity, acceleration, force

■ A vector is usually written in one of the following ways– In print the vector A would be written A (i.e., in boldface).– In writing the vector A would be written with an arrow over it, i.e., .

■ We sometimes have to combine vectors to produce a resultant vector.

Combining Vectors

■ If the vectors are perpendicular to one another there are three steps in determining the resultant vector

1. Draw the vectors with their tails touching.

2. Draw a parallel projection of each vector.

3. Draw the diagonal from where the tails touch to where the projections touch.

■ Note that this forms a right triangle so we can get the length of from the Pythagorean Theorem if we know the lengths of and .

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𝐶2=𝐴2+𝐵2

Components of Vectors

■ We can also resolve a vector into two component vectors that are perpendicular to one another.

1. Draw vertical and horizontal lines from the tail of the vector.

2. Draw the rectangle that encloses the vector.

3. The sides of the rectangle are the component vectors.

■ So is the component of in the y-direction and is the component of in the x-direction.

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Projectile Motion

■ We can resolve the motion of a projectile (say a cannonball, a shot put, a satellite, etc.) into its horizontal and vertical components.

– If we can neglect friction, the horizontal component is just motion with constant velocity, since no horizontal force is acting on the object.

– Similarly, the vertical component is just that of an object in free fall, i.e., a constant acceleration due to the gravitational force (which is vertical).

Components of Projectile Motion

Projectile Motion Simulation

■ Projectile Motion Simulation

■ For an initial speed of 15m/s and no air resistance, record the range, height and time for the following angles: .

■ What do you conclude from these measurements?

Projectile Motion Parameters

Projectile Motion Videos

■ Projectile Motion in Football

■ Projectile Motion in Hockey

■ Projectile Motion in Juggling

■ Mythbusters

Projectile Motion Simulator

■ Physics Classroom Simulator

■ Complete handout worksheet – due Monday 9/28

Projectile Motion Resources

CK12 Projectile Motion

Projectile Motion Simulation