"Application of the Average Speed ​​Formula and Displacement Difference Formula of Uniformly Variable Speed ​​Linear Motion" Research on Uniformly Variable Speed ​​Linear Motion PPT

Description

"Application of the Average Speed ​​Formula and Displacement Difference Formula of Uniformly Variable Speed ​​Linear Motion" Research on Uniformly Variable Speed ​​Linear Motion PPT

Part One: Learning Objectives

1. Master the three average speed formulas and their applicable conditions, and be able to use the average speed formula to solve related problems.

2. Can derive Δs=aT2 and use it to solve related problems.

PPT on the application of the average speed formula and displacement difference formula of uniformly variable linear motion, part 2: teacher-student interaction

The average speed formula of uniformly variable linear motion

Problem guide

An object moves in a straight line at a uniform speed. The initial speed is v0, and after a period of time, the final speed is v.

(1) Draw the v-t image of the object and find the average speed of the object during this period of time.

(2) Express the instantaneous speed vt2 at the intermediate moment in the image, and find vt2. (The results are represented by v0, v)

【Core Deepening】

Three average speed formulas and applicable conditions

1.v-=st, applicable to all movements.

2.v-=v0+v2, suitable for uniform speed linear motion.

3.v-=vt2, that is, the average speed within a period of time is equal to the instantaneous speed at the middle moment during this period, which is suitable for uniform linear motion.

Key ability 1 Application of average speed formula

The object first makes a uniformly accelerated linear motion with an initial velocity of zero, the acceleration a1 = 2 m/s2, accelerates for a period of time t1, and then continues to make a uniformly decelerated linear motion until the speed is reduced to zero. It is known that the time taken for the entire motion process is t = 20 s, the total displacement is 300 m, then the maximum speed of the object is ()

A. 15 m/s B． 30 m/s

C． 7.5 m/s D． Unable to solve

Key Ability 2: Average speed and instantaneous speed at intermediate moments

The average speed of a particle moving at a uniform speed along a straight line in the first 0.5 s is 2.45 m/s greater than its average speed in the first 1.5 s. Taking the direction of movement of the particle at the initial moment as the positive direction, then the particle's The acceleration is ()

A. 2.45 m/s2 B. -2.45 m/s2

C． 4.90 m/s2 D. -4.90m/s2

[Exercise to achieve standards]

1. A car that accelerates uniformly along a straight road takes 5 s to pass two telephone poles 50 m apart on the roadside. When it passes the second telephone pole, its speed is 15 m/s, and it passes the first electric wire. The speed of the rod is ()

A. 2 m/s b． 10 m/s

C． 2.5 m/s D． 5m/s

2. The car starts from rest and performs a linear motion with uniform acceleration. When the speed reaches v, it immediately performs a linear motion with uniform deceleration and finally stops. The total time of movement is t, then the total displacement of the car is ()

A.13vt B. 12vt

C.23vt D. 14vt

Displacement difference formula Δs=aT2

Problem guide

A car starts from point A and moves to the right in a uniformly accelerated straight line with acceleration a, reaches point B after time t, and then reaches point C after time t. What is sBC-sAB equal to?

【Core Deepening】

Displacement difference formula

1. In uniform linear motion, the difference in displacement within consecutive equal times T is a constant value, that is, Δs=s2-s1=aT2.

2. application

(1) Determine whether the object is moving in a straight line at a uniform speed

If Δs=s2-s1=s3-s2=...=sn-sn-1=aT2 holds, then a is a constant, indicating that the object moves in a straight line at a uniform speed.

(2) Find the acceleration

Using Δs=aT2, we can obtain a=ΔsT2.

There is an object moving in a straight line at a uniform speed. The displacements it passes through in two consecutive equal periods of time are 24 m and 64 m respectively. The consecutive equal periods are 4 s. What are the initial velocity and acceleration of the object?

Keywords: Free download of PPT courseware for compulsory course 1 of high school physics in Lu Ke Edition, PPT download on the application of the average speed formula and displacement difference formula of uniformly variable linear motion, PPT download of research on uniformly variable linear motion, .PPT format;

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Update Time: 2024-07-13

This template belongs to Physics courseware Lu Ke Edition High School Physics Compulsory Course One industry PPT template

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