Lesson plan

Topicmfea8706cf5b8782d_1528449000663_0Topic

Conversion of velocityvelocityvelocity units

Levelmfea8706cf5b8782d_1528449084556_0Level

Second

Core curriculummfea8706cf5b8782d_1528449076687_0Core curriculum

II. Solving problems using physical laws and relationships. Student:

3) converts time units (seconds, minutes, hours);

4) uses the concept of velocityvelocityvelocity to describe the rectilinear motion; calculates its magnitude (speed) and converts its units.

Timingmfea8706cf5b8782d_1528449068082_0Timing

45 minutes

General learning objectivesmfea8706cf5b8782d_1528449523725_0General learning objectives

Converting velocity units.

Key competencesmfea8706cf5b8782d_1528449552113_0Key competences

1. Distinguishes between speed units.

2. Converts speed units.

Operational (detailed) goalsmfea8706cf5b8782d_1528450430307_0Operational (detailed) goals

The student:

- recognises velocity units,

- calculates the speed and converts its units.

Methodsmfea8706cf5b8782d_1528449534267_0Methods

1. Student exercises.

2. Conventional lecture.

Forms of workmfea8706cf5b8782d_1528449514617_0Forms of work

1. Individual cooperation between the student and the teacher.

2. Learning by applying the known rules and solving problem tasks.

Lesson stages

Introductionmfea8706cf5b8782d_1528450127855_0Introduction

Task 1

List the known units of distance and time in the SI system.

Answer:

The unit of distance is meter [m], the unit of time is second [s].

Task 2

Describe how we determine the average speed.

Answer:

To calculate the average speed, divide the total distance travelled by the total time of travel.

Task 3

How can we graphically describe the motion of bodies?

Answer:

The motion of the bodies can be described graphically using the graphs of distance vs. time and speed vs. time.

Proceduremfea8706cf5b8782d_1528446435040_0Procedure

Task 4

Specify what the letters in the formula mean.

[Interactive graphics]

Task 5

Enter missing values.

a) $1 k m = . . . m = . . . c m$

b) $1 m = . . . c m$

c) $1 m = . . . k m$

d) $1 c m = . . . m$

e) $1 h = . . . min = . . . s$

f) $1 s = . . . min = . . . h$

Answer:

a) $1 k m = 1000 m = 100000 c m$

b) $1 m = 100 c m$

c) $1 m = \frac{1}{1000} k m$

d) $1 c m = \frac{1}{100} m$

e) $1 h = 60 min = 3600 s$

f) $1 s = \frac{1}{60} min = \frac{1}{3600} h$

Task 6

Which units are valid units of distancedistancedistance? Choose the correct answers.

a) day
b) light year
c) sea mile
d) metermetermeter
e) hectare
f) yard

Answer:

a) False. b) True. c) True. d) True. e) False. f) True.

Task 7

Which units are valid speed units? Choose the correct answers.

a) $m \cdot s^{- 1}$
b) $1 \frac{c m}{s}$
c) miles
d) knot
e) horsepower
f) mach

Answer:

a) True. b) True. c) False. d) True. e) False. f) True.

Task 8

Two cars are moving at speeds of $v_{1} = 30 \frac{}{m}$ and $v_{2} = 2, 4 \frac{k m}{}$ in the same direction, respectively. The second is behind the first one. Will the second car catch up with the first one?

Answer:

We convert the speed $v_{2}$ given in $\frac{k m}{m i n}$ to $\frac{m}{s}$ :

$2, 4 \frac{k m}{min} = 2, 4 \cdot \frac{1000 m}{60 s} = \frac{240 m}{6 s} = 40 \frac{m}{s}$

The secondsecondsecond car will catch up with the first car.

Task 9

A sprinter ran 100 m in 10 seconds. What was the speed of the sprinter? Give the result in $\frac{k m}{h}$ .mfea8706cf5b8782d_1527752256679_0A sprinter ran 100 m in 10 seconds. What was the speed of the sprinter? Give the result in $\frac{k m}{h}$ .

Answer:

Given:

$s = 100 m$

$t = 10 s$

Unknown:

$v = ?$

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

$v = \frac{100 m}{10 s}$

$v = 10 \frac{m}{s}$

$v = 10 \frac{m}{s} = 10 \cdot \frac{\frac{1}{1000} k m}{\frac{1}{3600} h} = 10 \cdot \frac{36 k m}{10 h} = 36 \frac{k m}{h}$

The sprinter ran at a speed of 36 $\frac{k m}{h}$ .

Task 10

A ship is moving at a speed of 7 knots (kn). At what speed the ship is moving in $\frac{k m}{h}$ ?
Assume $1 k n o t = 1 k n = \frac{1 n a u t i c a l m i l e}{h}, 1 n a u t i c a l m i l e = 1852 m$ .

Answer:

$7 k n = 7 \cdot 1852 \frac{m}{h} = 12964 \frac{m}{h} = 12, 964 \frac{k m}{h}$

The speed of the ship is $12, 964 \frac{k m}{h}$ .

Task 11

Convert the speed to the appropriate units.

a) $54 \frac{k m}{h} = . . . \frac{m}{s}$

b) $30 \frac{m}{s} = . . . \frac{k m}{h}$

c) $20 \frac{c m}{min} = . . . \frac{m}{s}$

d) $60 \frac{m}{s} = . . . \frac{k m}{min}$

Answer:

a) $15 \frac{m}{s}$

b) $108 \frac{k m}{h}$

c) $0, 0033 \frac{m}{s}$

d) $3, 6 \frac{k m}{min}$

Lesson summarymfea8706cf5b8782d_1528450119332_0Lesson summary

The speed unit in the SI system is meter per second $[\frac{m}{s}]$ .

In order to convert one unit of speed into another in the SI system, you should know the multiples and submultiples of the units of distance and time. Conversion of traditionally used speed units requires conversion of traditional length units into meters and units of time such as minutes, hours and days to second. We substitute the calculated values of the distance s and time t into:

v = \frac{s}{t}

to obtain the speed in meters per second.

Selected words and expressions used in the lesson plan

distancedistancedistance

hourhourhour

kilometerkilometerkilometer

metermetermeter

nautical milenautical milenautical mile

secondsecondsecond

time of motiontime of motiontime of motion

velocityvelocityvelocity

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velocity1

distance1

meter1

second1

hour1

kilometer1

nautical mile1

time of motion1

Scenariusz

Topicmfea8706cf5b8782d_1528449000663_0Topic

Lesson stages

Selected words and expressions used in the lesson plan