Topicmd269dc4c27fc887f_1528449000663_0Topic

Solving tasks and problems related to uniform rectilinear motionuniform rectilinear motionuniform rectilinear motion

Levelmd269dc4c27fc887f_1528449084556_0Level

Second

Core curriculummd269dc4c27fc887f_1528449076687_0Core curriculum

II. Solving problems using physical laws and relationships. The student:

I. 6) carries out calculations and writes down the result in accordance with the rounding rules and keeping the number of significant digits resulting from the accuracy of the measurement or from the data.

Timingmd269dc4c27fc887f_1528449068082_0Timing

45 minutes

General learning objectivesmd269dc4c27fc887f_1528449523725_0General learning objectives

Solving tasks and problems.

Key competencesmd269dc4c27fc887f_1528449552113_0Key competences

1. Developing the ability to read tasks with understanding.

2. Developing the ability of writing down mathematical notation in tasks individually.

3. Developing the ability to use the learned formula and definitions to solve problems.

Operational (detailed) goalsmd269dc4c27fc887f_1528450430307_0Operational (detailed) goals

The student:

- solves tasks,

- uses formulas and the correct notation for solving tasks.

Methodsmd269dc4c27fc887f_1528449534267_0Methods

1. Discussion.

2. Teaching by applying appropriate formula to solve problem tasks.

Forms of workmd269dc4c27fc887f_1528449514617_0Forms of work

1. Individual work.

2. Work with the whole class.

Lesson stages

Introductionmd269dc4c27fc887f_1528450127855_0Introduction

Task 1

Answer the questions:

1. How can we describe uniform rectilinear motion?
2. Give a definition of uniform rectilinear motion.
3. Give formula describing uniform rectilinear motion.
4. Draw typical graphs describing uniform rectilinear motion.

Answer:

1. Uniform rectilinear motion can be described by giving the trajectory which is the straight line and direction, orientation and value of the vector in this motion.

2. Uniform rectilinear motion means that the body is moving at a constant speed along a trajectory that is a straight line. In the uniform rectilinear motion, the body travels the same distances at regular intervals.

3. In uniform rectilinear motion, the speed is calculated from the formula:

where:
$v\left[\frac{m}{s}\right]$ - the speed of the body,
$s\left[m\right]$ - the distance travelled by the body,
$t\left[s\right]$ - time of travel.

The distance in uniform rectilinear motion should be calculated using the formula:

4. [Illustration 1]

Proceduremd269dc4c27fc887f_1528446435040_0Procedure

When solving physics problems, it is important to make a correct analysis of the phenomenon, define the associated physical quantities and use the correct formulas and their proper form.md269dc4c27fc887f_1527752263647_0When solving physics problems, it is important to make a correct analysis of the phenomenon, define the associated physical quantities and use the correct formulas and their proper form.

Task 2

Within 5 minutes the car covered 8 km. Calculate the speed of the car. Give the result in $\frac{km}{h}$.

Analysis:

Given:

$t=5min=\frac{1}{12}h$

$s=8km$

Unknown:

$v\left[\frac{km}{h}\right]=?$

Solution:

$v=\frac{s}{t}$

$v=\frac{8km}{\frac{1}{12}h}$

$v=96\frac{km}{h}$

Answer:

The speed of the car is 96 $\frac{km}{h}$.

[Interactive graphics]

The type of motion in uniform rectilinear motion is determined by the formula:

Task 3

Calculate the time it takes to cover 200 km if the car is traveling at a speed of 30 $\frac{m}{s}$. Give the result in minutes and hours.md269dc4c27fc887f_1527752256679_0Calculate the time it takes to cover 200 km if the car is traveling at a speed of 30 $\frac{m}{s}$. Give the result in minutes and hours.

Analysis:

Given:

$s=200km$

$v=30\frac{m}{s}=108\frac{km}{h}$

Solution:

$v=\frac{s}{t}$

$t=\frac{s}{v}[\frac{km}{\frac{km}{h}}=\frac{km\cdot h}{km}=1h]$

$t=\frac{200}{108}h$

$t=1,85h=111min$

Answer:

The time of travel is 1,85 h or 111 min.

Task 4

What distance will be covered by a cyclist riding at a speed of 6 $\frac{m}{s}$ during 4 hours. Give the result in hours.

Analysis:

Given:

$t=4h$

$v=6\frac{m}{s}=21,6\frac{km}{h}$

Unknown:

$s=?$

Solution: $v=\frac{s}{t}$

$s=v\cdot t[\frac{km}{h}\cdot h=km]$

$s=21,6\frac{km}{h}\cdot 4h$

$s=86,4km$

Answer:

Cyclist will travel 86,4 km.

Task 5

Kamil counted 13 posts in 1 minute during a car ride with his parents. The distance between the posts is 100 m. What is the speed of the car? Give the result in $\frac{m}{s}$ and $\frac{km}{h}$.

Analysis:

Given:

$n=13$ posts

$t=1min=60s$

$s=100m$

Unknown:

$v\left[\frac{m}{s}and\frac{km}{h}\right]=?$

Solution:

$s_c=(n-1)\cdot s$

$v=\frac{s_c}{t}$

$v=(n-1)\cdot \frac{s}{t}$

$v=\frac{(13-1)\cdot 100m}{60s}$

$v=20\frac{m}{s}=72\frac{km}{h}$

Answer:

The speed of the car is $20\frac{m}{s}=72\frac{km}{h}$.

Lesson summarymd269dc4c27fc887f_1528450119332_0Lesson summary

The distancedistancedistances in uniform rectilinear motion is calculated using the formula:

The formula for speed v in uniform rectilinear motion:

The formula for the time t in uniform rectilinear motion:

When solving tasks, remember about proper units calculation.

Selected words and expressions used in the lesson plan

distancedistancedistance

graphgraphgraph

time of motiontime of motiontime of motion

uniform rectilinear motionuniform rectilinear motionuniform rectilinear motion

velocityvelocityvelocity