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A rolling ball moves in a straight line on the ground is a combination of rectilinear and rotational motion.

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Similarities: 2 Marks
Differences: 3 Marks
Similarities
1) Both are undergoing rotational motion.
2) The distance of any point on the wheel or ceiling fan from the center of wheel or ceiling fan respectively will remain constant.
Differences
1) The ceiling fan is doing only rotational motion, whereas wheel is doing the translational and rotational motion.
2) The position of the center of ceiling fan does not change, whereas the position of the center of wheel changes after motion.
3) The ceiling fan is doing only one type of motion, whereas wheel is doing multiple motions at the same time.

Answer: Option C. -> Roadways, Waterways, Airways
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C
Roadways were the earliest mode of transportation followed by waterways and airways. The steam engine and the railroad were invented in the 19th century. Later, motorised boats and ships were developed as a means of water transport. The Wright brothers invented the aeroplane and gave the world another means of transport in the early 20th century.

Answer: Option B. -> False
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B
The unit of length should be chosen such that it is constant and same for everyone. SInce, everyone's footstep is not same, it cannot be used as a unit of length.

Answer: Option B. -> False
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B
They may encounter some human error, for example, parallax error. Parallax error arises when the reading is taken from random angles. It is a non-technical (human) error in which there is a difference in the readings if the readings are taken at different angles from the line of sight. Hence, to avoid this error, we must always take the readings by placing our eyes perpendicularly above the markings.

Answer: Option B. -> False
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B
When we see the trees from a moving train, their position is changing with respect to us. Hence, they appear to be moving. On the other hand, the position of co-passengers is not changing with respect to us, hence they appear to be stationary.

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Invention of wheel revolutionized the mode of transport.

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Each Point: 1 Mark
1) Circular motion and periodic motion
2) Rotational motion and periodic motion
3) Periodic motion or oscillatory motion
4) Rectilinear and rotational motion
5)Rectilinear motion

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Different modes: 2 Marks
Example for different modes: 1 Mark each
Transport modes are the means by which people and freight achieve mobility. They fall into one of three basic types, depending on over what surface they travel – land, water, and air.
Land: train, bus, and car.
Air: Aeroplanes, Spacecraft, and Gliders.
Water: Ships, Boats.

Answer: Option B. -> metre
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B
TheSI base unitsare seven units of measuredefined by the International System of Unitsas the basic set from which all other unitscan be derived. The SI unit of length is metre.