Potential Energy | Prep.1 | Unit 2 - Lesson 1 | Science

شرح ساينس الصف الأول الاعدادي لغات - الفصل الدراسي الثاني
شرح ساينس الاول الاعدادي - ترم تاني

لينك تحميل الملزمة
https://drive.google.com/file/d/1QTwa...

لينك تليجرام
https://t.me/mrahmedelbashagroup

In This Part :
Path of Movement
A set of points that the object passes through during its motion.
Distance (d)
The total length of any path taken by the object while moving from the starting point to the end point.
Displacement (s)
The shortest straight path connecting between the starting point and the end point in a constant direction.
Both distance and displacement are measured in the same unit, which is metre (m) or its multiples such as kilometre (km) or subdivisions such as centimetre (cm).

Speed (v)
The distance covered per unit time.

Calculation of speed:
Q1: Calculate the speed of an object that covers a distance of 8 m in 2 s

Q2: An object moves at a speed of 20 m/s, Calculate the distance that the object travels after one minute.

Work (W)
When a force acts on an object causing it to be displaced in the same direction of its effect, it is said that a work has been done on this object.
Applications of Work Done in Various Cases
Work (W)
The amount of energy required to move an object through a certain displacement in the same direction of the force which acts on it.

Calculation of work:
Q1: A person pushes an object with a force of 20 N, moving it in a straight line over a distance equals 50 m in the same direction of the force. Calculate the amount of work done.

Q2: To displace a box over 2 m distance, it requires a work equals 400 J
Calculate the force required to perform this work.

Controlling the variables
One of the skills in scientific research and the design of scientific comparative experiments.

Energy (E)
The ability to do work.

Potential Energy (PE)
The energy stored in an object as a result of the work done on it.

❶ Weight of the object (w):
A: The effect of object weight on its potential energy
Steps
1. Drop the small marble from a height of 50 cm above the surface of the sand.
2. Repeat the previous step with the other two marbles from the same height.

Observation
The depth of the crater (hole) formed by each marble in the sand increases with increasing the weight of the marble.

Conclusion
Controlled variables:
• Height of the marbles above the surface of the ground.
• Amount of sand.
Independent variable: Weight of the marbles.
Dependent variable: Depth of the crater (hole) formed by each marble.

 
❷ Height of the object above the surface of the ground level (h):
B: The effect of the object height above the ground surface on its potential energy.
Steps
1. Drop the marble from a height of 50 cm above the surface of the sand.
2. Repeat the previous step with increasing the height to 75 cm, and then to 100 cm
Observation
The depth of the crater formed by the marble increases as the height above the ground surface increases.
Conclusion
Controlled variables:
• Weight of the marble. • Amount of sand.
Independent variable:
Height of the marble above the ground surface.
Dependent variable: Depth of the crater formed by the marble each time.

It is concluded from the previous activities that:
The magnitude of which depends on two factors
• Weight of the object (w) measured in Newton (N).
• Height of the object above the surface of the ground level (h) measured in metre (m).

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