Movement of a branch of a tree in air is an example of _________.
Periodic motion because it repeats itself after some period of time.
Which of the following statements is correct?
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.
Who found that a pendulum of a given length always takes the same time to complete one oscillation?
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
The scale should be kept _______ the length while measuring a length.
When the bob of the pendulum is released after taking it slightly to one side, it:
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.
The motion of a rolling ball is an example of ________ motion.
Identify the types of motion from the images below.
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.
Three cars are running on the road with three different speeds: 78 mph, 59 mph, and 65 mph respectively. Calculate the average of these three speeds.
What would be the best unit to use to measure the tip of your pencil?
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).
Look at the following picture carefully.
Now read the following paragraph carefully and fill the blank with correct sequence of words.
A stone suspended with a non-stretchable thread makes a simple ________. When the pendulum is at rest, it is at position B. This is called the rest position or its ________. 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 __________.
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.
Two athletes take part in two separate races and cover different distances in different times. Kavya runs 2 km in 10 minutes and Yamini runs 5 km in 20 minutes on two different tracks. Which of the following statements is correct?
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.
Which of the following is not a unit of speed?
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.
Look at the picture carefully: Fill in the blanks using words: stationary, moving.
The potter at the railway station is _______ in relation to the train, but is_________ in relation to the bag on his head.
The potter at the railway station is moving in relation to the train, but is stationary in relation to the bag on his head.
Why is measurement important to us?
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.
Read the following two paragraphs. Analyze the situation and choose the correct options.
1. A bus runs from Kolkata to Guwahati. It covers a distance of 400 km in 7 hours and then a distance of 550 km in the next 7 hours.
2. Alisha takes part in a car race. She drives a distance of 70 km each in the first,second and third hours.
1 cm = ………. m
1m = 100 cm
so, 1 cm = 0.01 m
The length of the blank card shown below is:
It is clear from the given figure that the length of the blank card is 2.5 cm.
Which of the following objects cannot be used for measuring the length of a curved line?
An opisometer, also called a curvimeter, meilograph, or map measurer, is an instrument for measuring the lengths of arbitrary curved lines.
While reading an instrument, why is it important to place the eye in line with the reading?
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.
In 1790, the French created a standard unit measurement called
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).