Unit Test 2 Revision 2 April 2021

1. TRUE or FALSE? Looking at this picture of trees moved by wind’s push force? We, can actually and physically see the force. Could this be true? Explain why.

• TRUE

  We can see the force, we can see the movement of object (like these trees moving) pulled by force. Plus we also can feel the force.

• FALSE

  We cannot see the force, but we can see the movement of object (like these trees moving) pushed by force. Plus we also can feel the force.

TRUE or FALSE? Force Meter’s unit of measurement “Newton” was used in honour of Sir Isaac Newton; the scientist who discovered the principle of force and the laws of motion. Could this be true? Explain why?

• TRUE

  He discovered gravity when he suddenly saw an apple fell from a tree one day. He said that all objects are constantly pulled to the centre of the earth. Thus, it is called Weight in Newtons.

• FALSE

  He discovered electricity when he suddenly saw an apple fell from a tree one day. He said that all objects are constantly pushed to the centre of the earth. Thus, it is called Mass in Newtons.

3. TRUE or FALSE? A football player changes the direction of a ball by angling his foot towards the goal box. Could this be true? Explain why.

• FALSE

  In order to reach the goal box, a player needs to keep straight the balls direction by pressing his foot towards the goal box.

• TRUE

  In order to reach the goal box, a player needs to change the balls direction by angling his foot towards the goal box.

4. TRUE or FALSE? Squash force is different from squeeze force. Could this be true? Explain why.

• TRUE

  A squash is a flat push force. While squeeze is a force when you press something firmly from both sides at the same time.

• FALSE

  A squash is a circular twist force. While squeeze is a force when you pull something firmly from both sides at the same time.

5. TRUE or FALSE? Air Resistance is a type of friction. Can this be true? Explain why.

• FALSE

  It is a pulling force that pushes object downward slowing down the drag or pull of gravity.

• TRUE

  It is a contact force that pushes object upward slowing down the drag or pull of gravity.

6. Towards which direction does the water move in the picture? What is gravity? Select the correct conclusion.

• Conclusion:

  I found out that the water or liquid is moving upward towards the pull of gravity.

  Gravity is a man-made force that pulls all objects towards the centre of the earth.

• Conclusion:

  I found out that the water or liquid is moving downwards towards the pull of gravity.

  Gravity is a natural force that pulls all objects towards the centre of the earth.

7. What are the 3 natural forces? Water, wind and __________.

• a. push

• b. pull

• c. twist

• d. gravity

8. What are the 3 man-made forces? Push, pull and _________.

• a. wind

• b. water

• c. twist

• d. gravity

9. What kind of natural force makes the hydro-turbines at Niagara Falls generate electricity?

• wind force

• water force

• gravity

• twist force

10. What kind of natural force makes EWA Bahrain's Wind Turbines generate electricity?

• twist force

• gravity

• water force

• wind force