Warm Up 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. Find the total displacement between t=0 and t=30 10 8 6 4 v(m/s) Agenda • Warm Up • Review Test • The equations of Motion & constant acceleration • Equations of Motion Practice 2 t(s) 4 8 20 -2 16 12 24 28 -4 -6 -8 -10 Homework Quiz Friday Redo Incorrect Test Questions Make up Quiz Today After School
AP PhysicsTuesday 13.09.24Standards: Use the three equations of motion for 1D constant accelerationObjective: SWBAT understand where the equations of motion come from and WBAT employ them to solve problems Warm Up The 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 Agenda • Warm Up • Review Worksheets • Equations of Motion • Practice • Homework • Quiz Friday. • Wkbk p.7 1-6
AP PhysicsWednesday 13.09.25Standards: Use the three equations of motion for 1D constant accelerationObjective: SWBAT determine which equations to employ when solving acceleration problems Warm Up An 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 Agenda • Warm Up • Whole Class Practice Problem: Acceleration • In Class: Practice Finding which equations to use for particular problems. Homework HW p.13 ,4,5,7,10 HW p.8 *4,6 (be careful with units)
Warm Up A 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 15 m (B) 30 m (C) 60 m (D) 90 m (E) 180 m AP PhysicsThursday 13.09.26Standards: Use the three equations of motion for 1D constant accelerationObjective: SWBAT employ the three equations of motion to solve a variety of physics motion problems. Agenda • Warm Up • Review Homework • Acceleration Practice Homework Quiz Tomorrow (constant acceleration) Test Retakes available Acceleration Worksheet
Warm Up The 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 AP PhysicsFriday 13.09.27Standards: Standards: Use the three equations of motion for 1D constant accelerationObjective: SWBAT score 80% or higher on their quiz Agenda • Warm Up • Review HW • Take Quiz • More Equations of Motion Practice Homework Finish Today’s Classwork
3 equations of Motion There are three equations of motion that we use. I will derive 1&3 1 is created by combining a=Δv/Δt & Δv=v-v0 1. No Δx 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. 2. No v 3. 3 is created by substituting equation 1 into equation 2 No t 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.
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 v0and your unknown is t then equation 2 is going to be messy. 2a.Right now try to solve for t using: Δx=10m,Vo=20m/s,a=-9.8m/s2 2b.You can avoid this process by using equation 3 then equation 1. Now try solving the same problem using equation 1 & 3. 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 For each set of givens write down the equation/s you would use and explain why? 1. 2. 3. 4. 5. 6.
Constant Acceleration Problems • What is the acceleration of a car that goes from 20.0 m/s to 40.0 m/s in 250 m ? • 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? • 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. • 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? • 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? • 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? • 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? • 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?