Class 6 Viva ICSE Physics Chapter 4: Simple Machines Concept based questions: Higher Order Thinking Skills (HOTs)

Class 6 Viva ICSE Physics Chapter 4: Simple Machines Concept based questions: Higher Order Thinking Skills 

1. Aman was helping his grandmother in the kitchen. She gave him a jar of pickles to close. Aman noticed that the lid had spiral grooves inside, and he had to turn it several times just to move it down a tiny bit to seal the jar.

Q: Identify the simple machine used here.

A: The simple machine is a Screw.

Q: If the threads on the jar were further apart (a larger lead), would it be easier or harder to tighten? Why?

A: It would be harder. A larger lead means you move a greater distance with one turn, which requires more muscle power (effort). A smaller lead makes the work easier.

Q: Why is this lid called a "force multiplier"?

A: It is a force multiplier because Aman applies a small force by turning the lid, and the screw converts it into a very strong downward force to seal the jar tightly.

2. Rohan was going on an evening walk with his father. On the way, he crossed a construction site and saw that the workers were unloading heavy bricks and cement bags from a truck. He observed that the workers were using a long wooden ramp to get on and off the truck.

Question: What is the reason behind using the ramp structure? Explain how it helps the workers.

The Answer

1. Type of Machine:

The ramp is a simple machine called an inclined plane. It is a flat, sloping surface.

2. Makes Work Easier:

The reason for using the ramp is that it reduces the effort needed to move heavy cement bags. Lifting a heavy bag straight up into a truck is very difficult, but pushing it up a slope is much easier.

3. Force Multiplier:

The ramp acts as a force multiplier. This means it allows the workers to move a heavy load using a smaller amount of force.

3. During the morning assembly, Preeti saw the Principal pull a rope downwards to make the national flag rise to the top of a tall pole. She saw a small metal wheel at the top that the rope looped through.

Q: What is the name of this simple machine?

A: It is a Single Fixed Pulley.

Q: Does this machine reduce the amount of force needed to lift the flag?

A: No, it does not reduce the force. It only changes the direction of the force, making it easier to pull down rather than lift up.

Q: How could the workers make it easier to lift a very heavy load using pulleys?

A: They could use a Movable Pulley. Using more than one pulley (a pulley system) reduces the effort needed to lift heavy objects.

4. John and his father were hiking. They could take a short, very steep path or a long, gentle zigzag path to reach the top. They chose the zigzag path.

Q: Which simple machine does the zigzag path represent?

A: It represents an Inclined Plane.

Q: Why is the longer path easier to climb?

A: Because the slope is less steep. In an inclined plane, the longer the distance, the less effort is required to reach the same height.

Q: If the load is 200 N and the effort used on the ramp is 50 N, what is the Mechanical Advantage?

A: The Mechanical Advantage is 4.

M.A. = Load / Effort= 200/50 = 4