AP PhysicsMonday 13.09.23Standards: 1)a. Students should understand the general relationships between position velocity & acceleration for a particle along a straight line.

Objective: SWBAT understand where the equations of motion come from and WBAT employ them to solve problems.Agenda1. Warm Up2. Review Test3. The equations of Motion &

constant acceleration4. Equations of Motion Practice

HomeworkQuiz FridayRedo Incorrect Test QuestionsMake up Quiz Today After School

Warm Up

v(m/s)

t(s)

2

4

6

8

10

-2

-4

-6

-8

-10

4 8 12 16 20 24 28

Find the total displacement between t=0 and t=30

AP PhysicsTuesday 13.09.24Standards: Use the three equations of motion for 1D constant acceleration

Objective: SWBAT understand where the equations of motion come from and WBAT employ them to solve problems

Agenda1. Warm Up2. Review Worksheets3. Equations of Motion4. Practice

Homework• Quiz Friday.• Wkbk p.7 1-6

Warm UpThe graph below shows the velocity versus time for an object moving in a straight line. At what time after t = 0 does the object again pass through its initial position?(A) Between 0 and 1 s (B) 1 s (C) Between 1 and 2 s (D) 2 s (E) Between 2 and 3 s

AP PhysicsWednesday 13.09.25Standards: Use the three equations of motion for 1D constant acceleration

Objective: SWBAT determine which equations to employ when solving acceleration problems

Agenda1. Warm Up2. Whole Class Practice Problem:

Acceleration3. In Class: Practice Finding which

equations to use for particular problems.

HomeworkHW p.13 ,4,5,7,10HW p.8 *4,6 (be careful with units)

Warm UpAn object released from rest at time t=0 slides down a frictionless incline a distance of 1 meter during the first second. the distance traveled by the object during the time interval from t=1s to t=2s is a) 1m b) 2m c) 3m d)4m e)5m

AP PhysicsThursday 13.09.26Standards: Use the three equations of motion for 1D constant acceleration

Objective: SWBAT employ the three equations of motion to solve a variety of physics motion problems.

Agenda1. Warm Up2. Review Homework3. Acceleration Practice

HomeworkQuiz Tomorrow (constant acceleration)Test Retakes availableAcceleration Worksheet

Warm UpA 500-kilogram sports car accelerates uniformly from rest, reaching a speed of 30 meters per second in 6 seconds. During the 6 seconds, the car has traveled a distance of(A) 15 m (B) 30 m (C) 60 m (D) 90 m

(E) 180 m

AP PhysicsFriday 13.09.27Standards: Standards: Use the three equations of motion for 1D constant accelerationObjective: SWBAT score 80% or higher on their quiz

Agenda1. Warm Up2. Review HW3. Take Quiz4. More Equations of Motion Practice

HomeworkFinish Today’s Classwork

Warm UpThe velocity vs. time graph for the motion of a car on a straight track is shown in the diagram. The thick line represents the velocity. Assume that the car starts at the origin x = 0. At which time is the car the greatest distance from the origin?(A) t = 10 s (B) t = 6 s (C) t = 5s (D) t = 3s (E) t = 0 s

3 equations of Motion

There are three equations of motion that we use. I will derive 1&3

1.

2.

3.

Though you will not need to derive these, these illustrate a very important practice we undertake in Physics. There are situations where we can combine multiple equations in order solve problems that don’t seem to have a solution.

1 is created by combining a=Δv/Δt & Δv=v-v0

2 can be found by graphing the motion of an accelerating object on a v vs t graph and finding its area. It can be derived using calculus.

3 is created by substituting equation 1 into equation 2

No Δx

No v

No t

How to Use the 3 equations of motion

1. The # 1 rule is to use the givens to decide which equation to use. This equation can’t find an x, so don’t use it if you are given displacement or it is an unknown

This equation can’t find v, so don’t use it if you are given final velocity or it is an unknown.

This equation can’t find t, so don’t use it if you are given t or it is an unknown.

We will call this equation of motion #1

We will call this equation of motion #2

We will call this equation of motion #3

How to use the equations of motion day 2?

2. The # 2 rule is avoid quadratics! If one of your givens is a v0 and your unknown is t then equation 2 is going to be messy.

2b.You can avoid this process by using equation 3 then equation 1. Now try solving the same problem using equation 1 & 3.

2a.Right now try to solve for t using: Δx=10m,Vo=20m/s,a=-9.8m/s2

3. Remember what they are useful for. These equations work within the context of uniformly accelerated motion or constant acceleration. This includes no acceleration

Constant Acceleration Example

#3 p.13 The Boeing 747 can carry more than 560 passengers and has a maximum speed of about 9.70x102 km/h. After takeoff, the plane takes a certain time to reach its maximum speed. Suppose the plane has a constant acceleration with a magnitude of 4.8 m/s2. What distance does the plane travel between the moment its speed is 50% of maximum and the moment its maximum speed is attained?

Identifying Equations Practice

1. v 0 m/s

vo 40 m/s

Δx not given

a -3 m/s2

t ?

v not givenvo 40 m/s

Δx ?

a -3 m/s2

t 4.5s

2. 3. v ?vo -20 m/s

xo ?

a 2 m/s2

t 4.5s

x 10m

v 20 m/svo 5 m/s

xo ?

a 1.5 m/s2

t not given

x 50m

4. v 40mvo ?

xo 10m

a 3 m/s2

t ?

x 30m

5. v 60 m/svo -20 m/s

xo 30m

a ?

t ?

x 10m

6.

For each set of givens write down the equation/s you would use and explain why?

Constant Acceleration Problems1. What is the acceleration of a car that goes from 20.0 m/s to 40.0 m/s in 250 m ?2. 2. A runner accelerates from 1.0 m/s to 9.0 m/s in 5.0 s. How far did the runner

travel while accelerating?3. How long does it take for a plane to travel 1500.0 m in accelerating from 100.0 m/s

to 200.0 m/s.4. A car covers a distance of 400.0 m in 20.0 s while accelerating to a final velocity of

30.0 m/s at a rate of 1.5m/s2. What was its initial velocity?5. A car accelerates from rest at 1.0 m/s2 and covers a distance of 500.0 m. What is its

final velocity? What was its average velocity?6. A boat accelerates at 0.5 m/s2 over a distance of 200.0 m. Its initial velocity was 5.0

m/s. Calculate its final velocity. What was its average velocity?7. A jet accelerates at 2.0 m/s2 over a distance of 10000.0 m. If its final velocity was

250. m/s, what was its initial velocity? What was its average velocity?8. A truck accelerates from 15.0 m/s to 20.0 m/s over a distance of 50.0 m. What was

its acceleration• What was its average velocity?