JEE Main 26-Aug-2021 Shift 1 Solved Paper

The given situation is shown below as Applying law of conservation of energy, we get
Kinitial+Uinitial=Kfinal+Ufinal
Kinitial=0
⇒Uinitial=−1×10×

1

2

( 1m lie below DATUM level, so negative)
Kfinal=?
Ufinal=−3×10×

3

2

(3m lie below DATUMlevel, so negative)
0−1×10×

1

2

=Kfinal−3×10×

3

2

⇒−5=Kfinal−45
⇒Kfinal=45−5
= 40 J