شرح ساينس الصف الخامس الابتدائي لغات مستر احمد الباشا
ساينس خامسة ابتدائي

لينك تحميل الملزمة
https://drive.google.com/file/d/1G6h6sZqYm4gpsJ4LkqWqzhyBOaOUY9Qa/view?usp=sharing

لينك تليجرام
https://t.me/mrahmedelbashagroup

In this part :
► Earth rotates on its axis at high speed that reaches
more than 1600 kilometers per hour.
► We cannot only feel the high speed of Earth's rotation, but also it seems like Earth is standing still because we are moving with Earth, where everything attached to the surface of Earth moves at the same speed of Earth.

For example:
If you are sitting in a moving car looking out the window at nearby car moving in the same direction with the same speed, you will not feel that you are moving, but in fact you are traveling at many kilometers per hour.

Movement of objects in the sky
• Earth's rotation on its axis causes celestial bodies such as (the Sun and stars) appear to move in the sky such as:
- The Sun appears to rise in the east and set in the west.
- Stars seem to move in the sky at night, where some stars seem to rise and set like the Sun.

What Can Shadow Tell Us?
• Early, the ancient Egyptians used shadows cast by giant stone to know the time
of the day.
• Later, the ancient Egyptians invented the first timepiece that used to know the time called sundial (shadow clock).

Activity: we will make a sundial that used to collect data about
shadows.
Tools:

Steps:
1. Draw two lines that split the piece of carton vertically and horizontally as shown, where the intersection of these lines is the center of the carton piece.

2. Make a small hole at the center of carton piece and fix the plastic straw in it, then erase the vertical line.
3. Put the sundial in an open area facing the north direction and keep it in the same place without moving it during the activity.

4. Trace the shadow of the straw using three different colored pencils at different three hours which are : (10:00 a.m.), (12:00 p.m.) and (02:00 p.m.).
5. Remove the straw.
• For each shadow line, detect the following measurements:
- The length of each shadow line using the ruler.
- The angle between the shadow line and the horizontal line using the prorector.

Observation:
From the previous table we can observe that the lengths of the shadow lines and
their angles changed throughout the day.
Conclusions:
Throughout the day, the change in the position of the Sun in the sky due to the Earth's rotation affects the lengths and angles of shadows of objects on Earth.


بالتوفيق
مستر احمد الباشا