Projectile Motion – Zero Launch Angle

BellworkNotes – Zero Launch AngleFinish Video Analysis Lab

Mastering Physics AssignmentExit Pass

Question 4.2 Dropping a Package

You drop a package from a plane flying at constant speed in a straight line. Without air resistance, the package will:

a) quickly lag behind the plane while falling

b) remain vertically under the plane while falling

c) move ahead of the plane while falling

d) not fall at all

Bellwork

You drop a package from a plane flying at constant speed in a straight line. Without air resistance, the package will::

a) quickly lag behind the plane while falling

b) remain vertically under the plane while falling

c) move ahead of the plane while falling

d) not fall at all

Both the plane and the package have the

same horizontal velocity at the moment of

release. They will maintain this velocity in

the x-direction, so they stay aligned.

Follow-up:: what would happen if air resistance is present?

Question 4.2 Dropping a Package

Zero Launch Angle

Launch angle: direction of initial velocity with respect to horizontal

4-3 Zero Launch AngleThis is the trajectory of a projectile launched horizontally:

Zero Launch Angle

In this case, the initial velocity in the y-direction is zero. Here are the equations of motion, with x0 = 0 and y0 = h:

Zero Launch Angle

In this case, the initial velocity in the y-direction is zero. Here are the equations of motion, with x0 = 0 and y0 = h:

Use these equations to develop an equation for how the X and Y positions are related

Zero Launch Angle

Eliminating t and solving for y as a function of x:

This has the form y = a + bx2, which is the equation of a parabola.

The landing point can be found by setting y = 0 and solving for x:

Take Out Video Analysis Handout

• Under “Analysis/Questions”

• Let’s work on #5 in Lab Groups

• Then we’ll work on #s 3 & 4– Based on more general Projectile Motion concepts

• Finish last two questions and turn handout in– Finish both Paradigm ( Actual Plots ) and Lab handouts– Both will be graded

Mastering Physics Assignment

• Homework grade!!

• Chapter 4 (Start Now – Due by 2 AM 10/24)– Pay attention to what is practice, extra credit, etc.

• Chapter 5 (Can Start Saturday – Due by 2 AM 10/31)

• 2% of the 100 is deducted for each day late

a b dc

Question 4.5 Cannon on the Moon

For a cannon on Earth, the cannonball would follow path 2.

Instead, if the same cannon were on the Moon, where g =

1.6 m/s2, which path would the cannonball take in the same

situation?

a b dc

The ball will spend more

time in flight because

gMoon < gEarth. With more

time, it can travel farther

in the horizontal

direction.

For a cannon on Earth, the cannonball would follow path 2.

Instead, if the same cannon were on the Moon, where g =

1.6 m/s2, which path would the cannonball take in the same

situation?

Follow-up: which path would it take in outer space?

Question 4.5 Cannon on the Moon