Question

An electric pump rated at 1000W, takes 16 seconds to pump 100 kg of water out to a tank at a height of 10 m. what is the efficiency of the motor?​

Answer 1

Answer:

$\boxed{\sf Efficiency \ of \ the \ motor = 62.5 \ \%}$

Given:

Input Power ($\sf P_i$)= 1000 W

Mass (m) = 100 kg

Height (h) = 10 m

Time (t) = 16 s

To Find:

Efficiency of the motor

Explanation:

$\boxed{ \bold{Output \: power \: (P_o)= \frac{mgh}{t}}}$

$\sf \implies P_o = \frac{100 \times 10 \times 10}{16}$

$\sf \implies P_o = \frac{10000}{16}$

$\sf \implies P_o = \frac{ \cancel{16} \times 625}{ \cancel{16}}$

$\sf \implies P_o = 625 \: W$

$\boxed{ \bold{Efficiency = \frac{Output \ Power \ (P_o)}{Input \ Power \ (P_i) } \times 100}}$

$\sf \implies Efficiency = \frac{625}{10 \cancel{00}} \times \cancel{100}$

$\sf \implies Efficiency = \frac{625}{10}$

$\sf \implies Efficiency = 62.5 \: \%$

$\therefore$

Efficiency of the motor = 62.5 %