Q. A student uses a spring balance of least count 0.5 gwt to measure minimum force requited to just move a wooden block on a surface. He holds the spring vertically and observes that the pointer of the spring balance is 3rd division above the mark on the scale. He then pulled the block with this spring balance by increasing the pull gradually and when the pointer is at 38th division, the block just starts moving. He calculates the force.
Its correct value will be:
