Question

An elevator is designed to lift a load of $1000kg$ through $6$ floors of a building averaging $3.5m$ per floor in $6s$. Power of the elevator, neglecting other losses, will be:

• A. $3.43\times {10}^{4}W$
• B. $4.33\times {10}^{4}W$
• C. $2.21\times {10}^{4}W$
• D. $5.65\times {10}^{4}W$

Answer 1

The correct option is A $3.43\times {10}^{4}W$

Given the elevator is going up a height of $6\times 3.5m$ in 6 seconds
increase in potential energy of the system PE will be
$△PE=mgh$
now, power is defined as energy used or spent per unit time .i.e.
$P=△PE/△t$

$P=\frac{1000\times 9.8\times 6\times 3.5}{6}$

$P=3.43\times {10}^{4}W$