{"id":25703,"date":"2021-06-23T18:00:19","date_gmt":"2021-06-23T12:30:19","guid":{"rendered":"https:\/\/mcq-questions.com\/?p=25703"},"modified":"2022-03-02T10:36:11","modified_gmt":"2022-03-02T05:06:11","slug":"ncert-solutions-for-class-8-science-chapter-11","status":"publish","type":"post","link":"https:\/\/mcq-questions.com\/ncert-solutions-for-class-8-science-chapter-11\/","title":{"rendered":"NCERT Solutions for Class 8 Science Chapter 11 Force and Pressure"},"content":{"rendered":"

These NCERT Solutions for Class 8 Science<\/a> Chapter 11 Force and Pressure Questions and Answers are prepared by our highly skilled subject experts to help students while preparing for their exams.<\/p>\n

Force and Pressure NCERT Solutions for Class 8 Science Chapter 11<\/h2>\n

Class 8 Science Chapter 11 Force and Pressure Textbook Exercise Questions and Answers<\/h3>\n

Page 142-143<\/span><\/p>\n

Question 1.
\nGive two examples each of situations in which you push or pull to change the state of motion of objects.
\nAnswer:
\nExamples of pushing force:<\/p>\n

    \n
  1. A heavy box at rest is pushed to move it from one room to another. This brings the box in motion.<\/li>\n
  2. A player pushes a football using his foot. This changes the state of motion and direction of the ball.<\/li>\n<\/ol>\n

    Examples of pulling force:<\/p>\n

      \n
    1. Rope is pulled to draw water from a well. This brings the bucket of water in motion.<\/li>\n
    2. A drawer is pulled to open it. This brings the drawer in motion.<\/li>\n<\/ol>\n

      Question 2.
      \nGive two examples of situations in which applied force causes a change in the shape of an object.
      \nAnswer:
      \nExamples of forces that cause a change in the shape of an object are as follows:<\/p>\n

        \n
      1. Squeezing a plastic bottle changes its shape.<\/li>\n
      2. Deformation of clay by pressing it between the hands.<\/li>\n
      3. Rolling a chapati from a ball of dough.<\/li>\n<\/ol>\n

        Question 3.
        \nFill in the blanks in the following statements:
        \na. To draw water from a well we have to ……………… at the rope.
        \nb. A charged body ……………… an uncharged body towards it.
        \nc. To move a loaded trolley we have to ……………… it.
        \nd. The north pole of a magnet the ……………… north pole of another magnet.
        \nAnswer:
        \n(a) pull,
        \n(b) attracts,
        \n(c) push or pull,
        \n(d) repels<\/p>\n

        Question 4.
        \nAn archer stretches her bow while taking aim at the target. She then releases the arrow, which begins to move towards the target. Based on this information fill up the gaps in the following statements using the following terms:
        \n(muscular, contact, non-contact, gravity, friction, shape, attraction)
        \na. To stretch the bow, the archer applies a force that causes a change in its ………………
        \nb. The force applied by the archer to stretch the bow is an example of ……………… force.
        \nc. The type of force responsible for a change in the state of motion of the arrow is an example of a ……………… force.
        \nd. While the arrow moves towards its target, the forces acting on it are due to ……………… and that due to ……………… of air.
        \nAnswer:
        \n(a) shape,
        \n(b) muscular,
        \n(c) contact,
        \n(d) gravity, friction<\/p>\n

        \"NCERT<\/p>\n

        Question 5.
        \nIn the following situations identify the agent exerting the force and the object on which it acts. State the effect of the force in each case.
        \na. Squeezing a piece of lemon between the fingers to extract its juice.
        \nb. Taking out paste from a toothpaste tube.
        \nc. A load suspended from a spring while its other end is on a hook fixed to a wall.
        \nd. An athlete making a high jump to clear the bar at a certain height.
        \nAnswer:
        \na. In squeezing a piece of lemon, we make use of muscular force to extract its juice. This muscular force is exerted on the lemon by our fingers. As a result, the shape of the lemon gets changed.<\/p>\n

        b. We use our muscular force to take out paste from a toothpaste tube. The muscular force is exerted on the toothpaste tube by our fingers. As a result, the shape of the tube gets changed.<\/p>\n

        c. Here, the suspended load exerts a force on the spring and pushes the spring downwards. As a result, the spring gets stretched. Hence, its shape gets changed.<\/p>\n

        d. An athlete pushes the ground with his feet. His feet exert a muscular force on the ground. This allows him to jump over the bar. As a result, his state of motion gets changed.<\/p>\n

        Question 6.
        \nA blacksmith hammers a hot piece of iron while making a tool. How does the force due to hammering affect the piece of iron?
        \nAnswer:
        \nForce due to hammering changes the shape of the piece of iron.<\/p>\n

        Question 7.
        \nAn inflated balloon was pressed against a wall after it has been rubbed with a piece of synthetic cloth. It was found that the balloon sticks to the wall. What force might be responsible for the attraction between the balloon and the wall?
        \nAnswer:
        \nElectrostatic force is responsible for the attraction between the balloon and the wall. The balloon rubbed with a synthetic cloth gets electrically charged and sticks to the wall. This is because a charged object attracts another charged or uncharged object.<\/p>\n

        Question 8.
        \nName the forces acting on a plastic bucket containing water held above ground level in your hand. Discuss why the forces acting on the bucket do not bring a change in its state of motion.
        \nAnswer:
        \nIn this case, muscular force is acting in upward direction and the force of gravity is acting in downward direction. Both forces are acting in opposite directions and hence nullify the effect of each other. Due to this, there is no change in the state of motion of the bucket.<\/p>\n

        Question 9.
        \nA rocket has been fired upwards to launch a satellite in its orbit. Name the two forces acting on the rocket immediately after leaving the launching pad.
        \nAnswer:
        \nThe two forces acting on the rocket immediately after leaving the launching pad are:<\/p>\n