Question

Calculate power generated by tension in the string in first $4$ seconds of motion :-

• A. 250 W
• B. 750 W
• C. 1500 W
• D. 1000 W

Answer 1

Answer: (C)

For the block moving in upward direction
$T-10g=10a$
$\Rightarrow T=(10(g+g/2)=150N$
$s=\frac{1}{2}\left(\frac{g}{2}\right)(4{)}^2=40m$
$P=\frac{W}{t}=\frac{T\text{ s }}{t}=\frac{150\times 40}{4}=1500W$