Projectile Practice Quiz

Projectile Practice Quiz

We have a quiz tomorrow, are you ready? Let's practice and see.

Conceptual Questions

First we will start with some conceptual questions. This means we are going to ask questions that don't involve solving a math equation. See how you do. Let's do a little practice before we begin.

Projectile Properties

• Horizontal motion is constant (red arrow)

• Vertical motion is accelerating (green arrow)

• acceleration is only in the vertical direction and is always 9.8 m/s² down

• Blue arrow is the resultant or overall velocity (found by using a² + b² = c²

Multiple Choice

What is the vertical acceleration of a projectile?(neglect air resistance) 

• 0 m/s²
• 9.8 m/s²

Multiple Choice

What is the horizontal acceleration of a projectile?(neglect air resistance)  

• 0 m/s²
• 9.8 m/s²

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

Suppose Lemming A runs off the edge of the cliff at 2 m/s and Lemming B runs off the edge at 1 m/s. Which will hit the ground farther from the base of the cliff?

• A

• B

• Both at the same distance

Multiple Choice

Suppose Lemming A runs off the edge of the cliff at 2 m/s and Lemming B runs off the edge at 1 m/s. Which will hit the ground first?

• A

• B

• Both at the same time

Multiple Choice

Who do you agree with?

• Anita: “A projectile’s v_x changes because of gravity, and its v_y remains constant.”

• Barry: “Both v_x and v_y are constant.”

• Chris: “A projectile has no acceleration in the vertical dimension but it does accelerate horizontally.”

• Dave: “A projectile has vertical acceleration and a constant horizontal velocity”

Multiple Choice

Which vector pair (arrow pair) correctly represents the acceleration and velocity at point P?

Multiple Choice

At what point is v_x= 0 m/s?

• A

• B

• C

• D

• None of these points

Multiple Choice

At what point is v_y= 0 m/s?

• A

• B

• C

• D

• None of these points

Multiple Choice

If you increase initial horizontal velocity the time it takes to fall will...

• increase

• decrease

• stay the same

Multiple Choice

If you increase initial horizontal velocity the range will...

• increase

• decrease

• stay the same

Multiple Choice

If you increase your vertical distance the time it takes to fall will...

• increase

• decrease

• stay the same

Multiple Choice

If you increase your vertical distance the range will...

• increase

• decrease

• stay the same

Multiple Choice

If you increase your vertical distance the initial horizontal velocity will...

• increase

• decrease

• stay the same

Now let's practice vectors

• The resultant of a vector is found using Pythagorean Theorem

• You put the x and y component at 90 degrees and solve for the hypotenuse

• To solve for overall velocity you must find the resultant

• You add vectors in the same direction

• You subtract vectors in opposite directions

• All vectors need a magnitude, unit, and direction in the answer

Multiple Choice

Pat ran 6 m south, stopped for a rest, then continued running 5 m south. What is Pat's resultant displacement?

• 1 m south

• 11 m north

• 11 m south

• 1 m north

Multiple Choice

Connor sprinted 120 meters east and then sprinted 40 meters west. What is his resultant displacement?

• 160 meters west

• 80 meters west

• 160 meters east

• 80 meters east

Multiple Choice

Riley drove his car 40 m/s east and was blown by a wind of 8 m/s south. What is his resultant velocity?

• 43 m/s, south east

• 40.8 m/s, south east

• 42 m/s, south east

• 44.7 m/s, south east

Multiple Choice

Gaby runs 55 meters north and then 20 meters west. What is her resultant displacement?

• 58.5 m north west

• 3422 m north west

• 51.2 m north west

• 61 m north east

Multiple Choice

In practice B of the figure, which displacement is the horizontal component?

• 30 km, East

• 30 km, West

• 40 km, North

• 40 km, South

Multiple Choice

In practice A of the figure, What is the magnitude of the resultant displacement?

• 5 km

• 8 km

• 11 km

• 15 km

Multiple Choice

Which statement describes a vector?

• It has magnitude but no direction

• It has direction but no magnitude

• It has both direction and magnitude

• It has constant magnitude but no

  direction

Now lets do Projectile Math

• Step 1: Sketch the problem

• Step 2: Make an x and y column

• Step 3: Fill in acceleration: ALWAYS 0 for x and 9.8 m/s² down for y. V_iy is always 0.

• Step 4: Solve for time using d_y

• Step 5: Use time in BOTH columns and solve equations with your variable list

• 
  

Multiple Choice

Wiley Coyote is, predictably, chasing the Road Runner. Predictably again, he manages to overlook the fact that he is chasing the Road Runner along a cliff. As Wiley realizes that he has just run horizontally off a 472 m high cliff at 25 m/s, some important thoughts flash through his mind . . .

How fast, horizontally, will he be moving upon impact?

• 96 m/s down

• 96 m/s up

• 25 m/s either right or left

• 25 m/s up

Multiple Choice

Wiley Coyote is, predictably, chasing the Road Runner. Predictably again, he manages to overlook the fact that he is chasing the Road Runner along a cliff. As Wiley realizes that he has just run horizontally off a 472 m high cliff at 25 m/s, some important thoughts flash through his mind . . .

How fast, vertically, will he be moving upon impact?

• 96 m/s down

• 96 m/s up

• 25 m/s down

• 25 m/s up

Multiple Choice

A bullet is fired horizontally at a height of 1.3 meters at a velocity of 950 m/s. Assume no air resistance. How long until the bullet reaches the ground?

• 0.52 s

• 0.27 s

• 0.13 s

• 0.36 s

Multiple Choice

A ball is thrown horizontally at a height of 2.2 meters at a velocity of 65 m/s. Assume no air resistance. How far did the ball travel horizontally when it hit the ground?

• 14.3 m

• 30.55 m

• 65 m

• 43.55 m

Multiple Choice

A ball is launched horizontally with a horizontal velocity of 50 m/s and lands with a final vertical velocity of 75 m/s. What is the overall velocity of the ball?

• 8125 m/s down

• 90.1 m/s down

• 50 m/s right

• 75 m/s down

Poll

You are done, time for a poll. This will not count against your grade. Which topic do you want MORE practice on?

• Conceptual

• Vectors

• Math

• None, I understand it all!