(a) A 10-kg block is supported bycord that runs to a spring scale, which is supported by another cord from the ceiling as shown in fig. What is the reading on the scale? (b) In Fig. the block is supported by a cord that runs around a pulley and to a scale. The opposite end of the scale is attached by a cord to a wall. What is the reading of the scale? (c ) In fig. the wall has been replaced with a second 10-kg block, what is the reading on the scale now? .

(a) A 10-kg block is supported bycord that runs to a spring scale, whi

1.	(a) A 10-kg block is supported bycord that runs to a spring scale, which is supported by another cord from the ceiling as shown in fig. What is the reading on the scale? (b) In Fig. the block is supported by a cord that runs around a pulley and to a scale. The opposite end of the scale is attached by a cord to a wall. What is the reading of the scale? (c ) In fig. the wall has been replaced with a second 10-kg block, what is the reading on the scale now? .
Answer» Solution :In all the three CASES the spring balance reads 10 kg. Let us cut a section inside the spring as shown in FIG As each part of the spring is at REST , so `F=T`. As the block is STATIONARY, so `T=F=100N`.