Page 151 - Active Science 5 Ebook and Activity

3. In a lever of second order, _____________ lies in the centre.
4. An inclined plane is a _____________.

5. A screw is an inclined plane wrapped around a _____________.
6. Levers are grouped into _____________ types.
7. A wheel with a _____________ attached to it is called a wheel and axle arrangement.

C. Match the following.
1. See-saw a. Inclined plane

2. Bottle opener b. Wedge
3. Ramp on gate c. To move heavy loads easily
4. Screw d. Lever of first class

5. Axe e. Inclined plane wrapped around a long rod
6. Wheels f. Lever of the second class

D. State whether the following statements are true or false.
1. A machine makes the work easier as it increases the applied force. _____

2. In a lever of the first class, effort lies in the centre. _____
3. Knife is an example of lever of second class. _____

4. Forceps and spades are examples of lever of third class. _____
5. A jack is used to lift heavy objects. _____

6. With the help of wheels, we can change the direction of the force applied. _____

E. Write two examples each.
1. Simple machine ________________________________________

2. Third type of levers ________________________________________
3. Wedge ________________________________________
4. Wheel and axle ________________________________________

5. Inclined plane ________________________________________

F. Short Answer Questions.
1. What is a simple machine?

2. List any three advantages of machines.
3. Classify the following into levers of first, second or third class.

wheelbarrow, forceps and weighing balance, arm, tin sheet, bottle opener, knife, scissors

4. Why do carpenters prefer screws as compared to nails?
5. What is a complex machine?

G. Long Answer Questions.

1. How do you hoist a flag on a high pole?
2. What is an inclined plane? What is it used for?

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