Why can a pace or a footstep not be used as a standard unit of length?

Four children measure the length of a table which was about 2 m. Each of them used different ways to measure it.

(i) Sam measured it with a half metre long thread.

(ii) Gurmeet measured it with a 15 cm scale from her geometry box.

(iii) Reena measured it using her hand span.

(iv) Salim measured it using a 5 m long measuring tape.

Which one of them would get the most accurate length? Give reason for your answer.

Which of the following does not express a time interval?

While measuring the length of a knitting needle, the reading of the scale at one end is 3.0 cm and at the other end is 33.1ccm. What is the length of the needle?

The height of a person is 1.65 m. Express it into cm and mm.

Correct the following.

(i) The motion of a swing is an example of rectilinear motion.

(ii) 1m = 1000 cm

Four pieces of wooden sticks A,B,C and D are placed along the length of 30 cm long scale as shown in Fig. 10.4. Which one of them is 3.4 cm in length?

A piece of ribbon folded five times is placed along a 30 cm long measuring scale as shown in Fig. 10.2.

The length of the ribbon is between

Fig. 10.1 shows a measuring scale which is usually supplied with a geometry box. Which of the following distance cannot be measured with this scale by using it only once?

The distance between Delhi and Mumbai is usually expressed in units of

Arrange the following lengths in their increasing magnitude:

1 meter, 1 centimeter, 1 kilometer, 1 millimeter.