A drilling machine operates in two distinct phases while boring a hole in a steel plate.

PHYSICS · Multi-part · CBSE · Physics · Work, Energy and Power · Work, Energy and Power

Problem

A drilling machine operates in two distinct phases while boring a hole in a steel plate. (i) In the first

20\,\text{s}

it performs

15\,\text{kJ}

of work. Calculate the average power during this phase. (ii) Due to tool wear, in the next

10\,\text{s}

it performs only

6\,\text{kJ}

of work. Compute the average power during this second phase. (iii) Determine the overall average power for the entire

30\,\text{s}

operation. (iv) The manufacturer claims that the machine has a constant power output of

600\,\text{W}

. Using your calculations from parts (i)–(iii), evaluate the accuracy of this claim and state whether it is justified.