A. State whether the statements given below are True or False:
1. Swinging of our arms or legs are periodic motions.
2. Beating of our heart is non-periodic motion.
3. Periodic motion helps us to measure time.
4. In a circular motion; the objects or any of their parts move in a circular path.
5. Motion of second’s hand of a clock is rectilinear.
6. SI unit of length is ‘Foot’.
7. For measuring large distances metre is not a convenient unit.
8. Motion of a vehicle on a straight road is a rectilinear motion.
9. Marchpast of soldiers in a parade is a periodic motion.
10. Motion of second’s hand in a clock is a circular motion.
11. In rotational motion whole body moves about an axis.
12. The result of a measurement is expressed in two parts.
13. Deficiency of vitamin A makes our bones weak.
14. Deficiency of iron causes paleness.
15. Calcium is necessary for strong bones and teeth.
16. Deficiency of vitamin B helps to increase our appetite.
17. Deficiency of vitamin D causes swollen and bleeding gums.
18. Carbohydrates are the main source of energy in our diet.
19. Expensive food is not always the best food
20. Protein is a staple food.
21. Haemoglobin is a carbohydrate.
22. Cotton and paper are carbohydrates.
23. Tomatoes contain vitamin C.
24. Eating lady finger makes you good in mathematics.
25. Paper can be recycled to get useful products.
26. Drains get choked due to plastics thrown by us.
27. Plastics give out harmful gases on heating or burning.
28. Redworms eat upon green leaves on trees and make compost.
29. Plastics are eco-friendly.
30. Cooking of rice is a physical change.
31. Breaking of a China (porcelain) dish is a chemical change.
32. Rusting of iron is an irreversible change.
33. Eruption of a volcano is a reversible change.
34. Formation of clouds is an irreversible change.
35. Conversion of a solid to liquid by heating is called fusion.
36. Change of seasons is a natural change.
37. Pressure is equal to the force per unit second.
Answers
Answer:
swinging of arms or legs are periodic motion
The following are true or false of the above statement -
1. True - If a body recurs its motion along a definite path, about a certain point after a fixed interval of time is called the periodic motion. Swinging is an example of periodic motion.
2. True - Beating of the heart of a healthy person is an example of non-periodic motion.
3. True - Periodic events are used for the measurement of time. The periodic motion of a pendulum has been used to make clocks and watches.
4. True - In a circular motion, the object moving in a circular path experiences a centripetal force.
5. False - The motion of the entire second hand is rotational motion, not rectilinear motion.
6. Flase - SI unit of length is 'meter'
7. True - Fir measuring large distances kilometer is used.
8. False - Motion of a vehicle on a straight road is a straight line.
9. False - Marchpast of soldiers in a parade is a rectilinear motion.
10. True - Motion of a second's hand is a circular motion, as it is moving in a circular path.
11. True - When a body moves about on its own axis, then it is called rotational motion.
12. True - The result of measurement is expressed in two parts. The first part is quantity, and the second part is the unit of measurement.
13. True - Deficiency of Vitamin A severely affects the growth of bones.
14. True - Deficiency of Iron causes paleness or pale skin.
15. True - Calcium plays a vital role in the growth of bones and teeth.
16. True - Deficiency of Vitamin B12 helps to increase the appetite.
17. True - Deficiency of Vitamin D causes swollen and bleeding gums.
18. True - Carbohydrate is the main source of energy and hence is the main source of energy in the diet.
19. True - Expensive food is often processed or better marketed. Hence, expensive foods are not always the best food.
20. True - Stable food is those food that is eaten routinely. So, protein is the staple food.
21. False - Haemoglobin is a protein.
22. True - Cotton and paper are cellulose, hence they are carbohydrates.
23. True - Tomato is the main source of Vitamin C.
24. True - Okra is relatively high in nutrients, and are the main function like phosphorus and Vitamin A, hence makes good in mathematics.
25. True - Paper can be recycled into various useful products.
26. True - Plastics are harmful and can choke up the drains.
27. True - Plastic gives out harmful gases like sulfur dioxide, carbon dioxide.
28. True - Redworms eat upon green leaves on trees and are used to make the compost. These compost are used as fertilizers.
29. Flase - Plastics are harmful to the environment, are not eco-friendly.
30. False - Cooking of rice is irreversible so it is a chemical change.
31. True - Breaking a China (porcelain) dish is a chemical change.
32. True - Rusting of iron can not be reversed. Hence it is an irreversible change.
33. True - Eruption of the volcano is a chemical change.
34. True - Formation of cloud can not be reversed back. Hence it is an irreversible change.
35. False - Conversion of solid to liquid by heating is called melting.
36. True - Change of season is a natural change, and can not be influenced manually.
37. False - Pressure is equal to the force applied per unit area.