Figure (5-Q1) shows a light spring balance connected to two blocks of mass 20 kg each. The graduations in the balance measure the tension in the spring. (a) What is the reading of the balance? (b) Will the reading change if the balance is heavy, say 20 kg? (c) What will happen if the spring is light but the blocks have unequal masses?

Question

Philoid · Accepted Answer

It is given that mass of the block is m=20kg

A) The reading of the balance = Tension in the string

And tension in the string = 20 ×10 = 200 N

So, the reading of the balance = = 200 N

B) If the balance is heavy, the reading will not change because the weight of spring balance does not affect the tension in the string

Therefore, Tension is equal to

C) If the blocks have unequal masses, the spring balance will accelerate towards the block with heavy higher mass with an acceleration a.

Then, Reading = tension in the string.

Suppose m1 > m2.

Then tension in the string,