Olympiad Test: Motion And Measurement Of Distances - Class 6 MCQ

Periodic motion because it repeats itself after some period of time.

A pace or a footstep cannot be used as a standard unit of length because the length of footstep, forearm length and hand span of different person is different. Since standard units must be similar at all places of world and in all kinds of conditions. It should not depend upon body parts and natural phenomenon.

The scientist who found that a pendulum of a given length takes the same time to complete one oscillation was Galileo Galilei. GALILEO GALILEI was the scientist who found that the pendulum of a given length always takes the same time to complete one oscillation

Along is the correct ✔ answer. 
It should be kept along the length while measuring the length because if it is prependicular the measurement can't be done, if it is inclined then the measurement will be more or less, if it is away then we have to estimate and better than estimating using span scale is much better. 

When the bob of the pendulum is released after taking it slightly to one side, it begins to move to and fro. The to and fro motion of a simple pendulum is an example of a periodic or an oscillatory motion.

Rotational is the correct ✔ answer.
In rotational motion, every particle of the body moves in a circle. For example, an object ,say a ball  is in rolling. So, the ball is in rotational motion.

Rotational motion: Purely rotational motion occurs if every particle in the body moves in a circle about a single line. This line is called the axis of rotation
Linear motion:  Moving in a straight line.
Periodic motion: Motion repeated in equal intervals of time.

67.3 mph is the correct ✔ answer. 
We have to calculate the average, for that we have to sum up :-  ( 78+59+65) = 202
For average :-    202 / 3  =   67.3 mph

We can use this unit for measuring the length of a pencil, the width of a book etc. but this unit is too big to measure the thickness of a pencil. So we use another unit called millimeter (mm).

A stone suspended with a non-stretchable thread makes a simple pendulum. When the pendulum is at rest, it is at position B. This is called the rest position or its mean position. When it swings, it moves from B to A, back to B, from B to C and back to B. This completes one full swing of the pendulum. Each swing is called one oscillation.

If Kavya takes 10 minutes to cover 2 km, then in 1 minute, she will cover  2 km ÷ 10 = 0.2 km (using the formula: speed = distance travelled ÷ time taken) Similarly, if Yamini takes 20 minutes to cover 5 km, then in 1 minute she will cover 5 km ÷ 20 = 0.25 km.

The SI unit of speed is the metre per second. There are other units of speed such as kilometers per hour, feet per second, mach, miles per hour, rev, rpm, light-year, knots, km per minute and meter per minute.

The potter at the railway station is moving in relation to the train, but is stationary in relation to the bag on his head.

Without the ability to measure, it would be difficult for scientists to conduct experiments or form theories. Not only is measurement important in science and the chemical industry, it is also essential in farming, engineering, construction, manufacturing, commerce, and numerous other occupations and activities.

First statement is non - uniform and second is uniform is the correct ✔ answer. 
Uniform motion is when a body travels equal distance in equal interval of time. A body is said to be in non-uniform motion if it travels unequal distances in equal intervals of time.

1m = 100 cm
so, 1 cm = 0.01 m

An opisometer, also called a curvimeter, meilograph, or map measurer, is an instrument for measuring the lengths of arbitrary curved lines.

Parallax is a deceptive change of the position of an object which is observed while the position of the observer changes. Position of eye at all volumetric vessels must be at the same level as the meniscus. If not, the parallax will cause an error while reading the position of the meniscus of a liquid in a burette.

System of units is called International System of Units (SI units). In 1790, the French created a standard unit of measurement called the metric system. SI unit of length is metre (m) while for large distances; the unit is kilometer (km).

The standard unit of length in the International System of Units (SI) is the meter (m).

The meter is the base unit for measuring length and is used worldwide for scientific, engineering, and everyday measurements.