امتحان ساينس الوحدة الثانية مع الاجابات اولى اعدادي مقرر ابريل

هذه معاينة نصية للأسئلة للاطّلاع والمراجعة فقط. لخوض الاختبار تفاعليًّا مع تصحيح آلي ونتيجة فورية، اضغط زر «ابدأ الاختبار» أدناه.

1. What factors determine the kinetic energy of any object?
   • أ. Mass and velocity
   • ب. Velocity and height
   • ج. Weight and velocity
   • د. Mass and height
2. If an object has a mass of 2 kg and moves at a velocity of 3 m/s, its kinetic energy is:
   • أ. 9 Joules
   • ب. 12 Joules
   • ج. 18 Joules
   • د. 6 Joules.
3. When the velocity of an object doubles while its mass remains constant, its kinetic energy:
   • أ. Increases fourfold.
   • ب. Remains constant.
   • ج. Decreases by half
   • د. Doubles
4. When an object falls from a height, its potential energy converts into:
   • أ. Kinetic energy.
   • ب. Chemical energy.
   • ج. Light energy
   • د. Thermal energy.
5. An object with a mass of 5 kg is placed at a height of 4 m above the ground. Its potential energy is:
   • أ. 200 Joules
   • ب. 100 Joules.
   • ج. 20 Joules.
   • د. 50 Joules.
6. When an object reaches the ground after falling, its potential energy is:
   • أ. Zero.
   • ب. At its maximum value.
   • ج. Undefined
   • د. Equal to its kinetic energy.
7. When a pendulum is at its highest point, its energy is:
   • أ. Only potential energy.
   • ب. Zero
   • ج. A combination of kinetic
   • د. Only kinetic energy.
8. When the pendulum passes through its equilibrium position (lowest point), its energy is:
   • أ. Only kinetic energy.
   • ب. Zero
   • ج. Only potential energy.
   • د. A combination of kinetic and potential energy.
9. At the midpoint between the highest point and the equilibrium position of a pendulum:
   • أ. Potential energy = Kinetic energy.
   • ب. Potential energy > Kinetic energy.
   • ج. Potential energy < Kinetic energy.
   • د. Potential energy = Zero
10. he mechanical energy of an object is equal to:
    • أ. The sum of its potential and kinetic energy.
    • ب. The difference between its potential and kinetic energy.
    • ج. The product of its potential and kinetic energy.
    • د. Only its potential energy
11. If the mechanical energy of an object is 100 Joules and its potential energy is 60 Joules, its kinetic energy is:
    • أ. 40 Joules
    • ب. 100 Joules.
    • ج. 60 Joules.
    • د. 160 Joules.
12. When an object is in free fall, its mechanical energy remains constant because:
    • أ. Potential energy converts into kinetic energy.
    • ب. There is no friction.
    • ج. Kinetic energy converts into potential energy.
    • د. All of the above
13. The kinetic energy of an object depends on its direction of motion.
    • أ. False
    • ب. True
14. Kinetic energy and mechanical energy always have the same value.
    • أ. False
    • ب. True
15. The unit of velocity in the kinetic energy equation is:
    • أ. Meter/second
    • ب. Newton
    • ج. Meter/second squared
    • د. Joule
16. If the kinetic energy of an object is 200 Joules and its mass is 4 kg, its velocity is:
    • أ. 10 m/s
    • ب. 2.5 m/s
    • ج. 20 m/s
    • د. 5 m/s
17. Kinetic energy depends on:
    • أ. The square root of time
    • ب. The square root of mass
    • ج. The square of velocity
    • د. The square of mass
18. An object with a kinetic energy of 9 J moves at a velocity of 3 m/s. What is its mass?
    • أ. 2 kg
    • ب. 4 kg
    • ج. 5 kg
    • د. 6 kg
19. When the mass of an object doubles, its kinetic energy also doubles.
    • أ. True
    • ب. False
20. What is the unit of kinetic energy?
    • أ. Joule
    • ب. Watt
    • ج. Meter/second
    • د. Newton
21. Kinetic energy is inversely proportional to the velocity of an object.
    • أ. False
    • ب. True
22. When an object is in free fall from a certain height:
    • أ. Mechanical energy remains constant
    • ب. Both potential and kinetic energy increase together
    • ج. Potential energy is entirely converted into kinetic energy
    • د. Kinetic energy is entirely converted into potential energy
23. An object has a kinetic energy of 75 J and a mass of 1.5 kg. What is its velocity?
    • أ. 10 m/s
    • ب. 5 m/s
    • ج. 100 m/s
    • د. 20 m/s
24. What is the role of the Aswan High Dam in generating electricity?
    • أ. Converting the potential energy of water into kinetic energy to generate electricity
    • ب. Converting electrical energy into mechanical energy
    • ج. Storing potential energy and converting it into thermal energy
    • د. Converting kinetic energy into potential energy
25. How does a wrecking ball work?
    • أ. Converting stored potential energy into kinetic energy to demolish buildings
    • ب. Converting kinetic energy into potential energy
    • ج. Converting electrical energy into kinetic energy
    • د. It is not used in demolishing buildings
26. Where is potential energy at its maximum?
    • أ. When the object is at its highest point from its original position
    • ب. When the object passes through its original position
    • ج. When the object reaches the ground
    • د. At the start of motion
27. Why should lifting heavy objects in a way that harms the spine be avoided?
    • أ. Because it can increase pressure on leg muscles
    • ب. Because it can increase potential energy
    • ج. Because the load should be on the back, not the legs
    • د. Because lifting heavy objects reduces kinetic energy
28. What happens when an object is released from a certain height in free fall?
    • أ. Kinetic energy increases, and potential energy decreases
    • ب. Potential energy increases, and kinetic energy decreases
    • ج. Both potential and kinetic energy remain constant
    • د. Neither energy changes
29. What is the mathematical formula for kinetic energy?
    • أ. KE = ½ × m × v²
    • ب. KE = m × v
    • ج. KE = ½ × v²
    • د. KE = ½ × m × v