Question

A strong person may do certain work in relatively less time. A more powerful vehicle would
complete a journey in a shorter time than a less powerful one. We talk of the power of machines
like motorbikes and motorcars. The speed with which these vehicles change energy or do work is
the basis for their classification Power measures the speed of work done, that is, how fast or slow
work is done
(a) Define power
(b)Define the SI unit of power.
(c)What is the relation between KWH and Joutes?
(d)A lamp consumes 1000 J of electric energy in 10 sec.​

Answer 1

Answer:

power is that is consideted by any object

Answer 2

Answer:-

(a) POWER: The rate of doing work by a particle is known as power. Further, it is denoted by 'P'.

(b) The SI unit of power is 'W' (watts) which is equal to 1 joule per second.

(c) $\tt{1 kWh = 1000 J \ s^{-1} \times 1 hour}$

⇒ $\tt{1 kWh = 1000 J \ s^{-1} \times 3600 s}$

⇒ $\tt{ 1 kWh = 3.6 \times 10^6 \ J }$ (relationship).

(d) Energy consumed = $\tt{1000 \ J }$

Time taken = $\tt{10 \ s }$

As, $\tt{P = \dfrac{E}{t}}$,

∴ $\tt{ P = \dfrac{1000 \ J}{10 \ s}}$

⇒ $\tt{P = 100 \ W}$.