Q. 65.0( 3 Votes )
Observe Figure 13.3.
The time period of a simple pendulum is the time taken by it to travel from
A. A to B and back to A.
B. O to A, A to B and B to A.
C. B to A, A to B and B to O.
D. A to B.
Time period is defined as the time taken by the pendulum to complete one oscillation. Here A to B and again back to A complete one oscillation.
Rate this question :
Which of the following are not correct?
i. The basic unit of time is second.
ii. Every object moves with a constant speed.
iii. Distances between two cities are measured in kilometers.
iv. The time period of a given pendulum is not constant.
v. The speed of a train is expressed in m/h.NCERT Science
A simple pendulum takes 32 s to complete 20 oscillations. What is the time period of the pendulum?NCERT Science
You can perform an interesting activity when you visit a park to ride a swing. You will require a watch. Make the swing oscillate without anyone sitting on it. Find its time period in the same way as you did for the pendulum. Make sure that there are no jerks in the motion of the swing. Ask one of your friends to sit on the swing. Push it once and let it swing naturally. Again, measure its time period. Repeat the activity with different persons sitting on the swing. Compare the time period of the swing measured in different cases. What conclusions do you draw from this activity?NCERT Science
Make a model of a sand clock which can measure a time interval of 2 minutes (Fig. 13.17).
You can make your own sundial and use it to mark the time of the day at your place. First of all find the latitude of your city with the help of an atlas. Cut out a triangular piece of a cardboard such that its one angle is equal to the latitude of your place and the angle opposite to it is a right angle. Fix this piece, called gnomon, vertically along a diameter of a circular board a shown in Fig. 13.16. One way to fix the gnomon could be to make a groove along a diameter on the circular board.
Next, select an open space, which receives sunlight for most of the day. Mark a line on the ground along the North-South direction. Place the sundial in the sun as shown in Fig. 13.16. Mark the position of the tip of the shadow of the gnomon on the circular board as early in the day as possible, say 8:00 AM. Mark the position of the tip of the shadow every hour throughout the day. Draw lines to connect each point marked by you with the centre of the base of the gnomon as shown in Fig. 13.16. Extend the lines on the circular board up to its periphery. You can use this sundial to read the time of the day at your place. Remember that the gnomon should always be placed in the North-South direction as shown in Fig. 13.16.
Collect information about time measuring devices that were used in the ancient times in different parts of the world. Prepare a brief write up on each one of them. The write up may include the name of the device, the place of its origin, the period when it was used, the unit in which the time was measured by it and a drawing or a photograph of the device, if available.NCERT Science
The average age of children of Class VII is 12 years and 3 months. Express this age in seconds.NCERT - Exemplar Science
Fig. 13.4 shows an oscillating pendulum.
Time taken by the bob to move from A to C is t 1 and from C to O is t 2 . The time period of this simple pendulum isNCERT - Exemplar Science
Observe Figure 13.3.
The time period of a simple pendulum is the time taken by it to travel fromNCERT - Exemplar Science