A. Circle the correct answer, complete the dialogue below.
Herman : | Oh no, I cannot get the top off this bottle! |
Mary : | This is because yours hands are (1) dry, oily as you have just eaten. |
Herman : | Is there any problem with that? |
Mary : | This will cause the (2) friction, force between your fingers and the top of the bottle to become (3)smaller, bigger. |
Herman : | Then, what should I do? |
Mary : | Clean and (4)warm, dry your hands first so that you can apply a (5)smaller, bigger force and open the top more easily, |
Herman : | Thanks for your advice. |
Mary : | You are welcome. |
B. State whether the following statements are true or false.
1. A force is needed to do work. | ||
2. A goalkeeper exerts an opposing force on the ball when he catches it. | ||
3. Force can make a stationary objects moves but cannot make a moving object stops. | ||
4. The rougher the surface, the further the moving object can travel. | ||
5. Friction is always useful in our everyday life. | ||
6. A spring becomes shorter when compressed due to friction. |
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