Physics | JEE Mains 2022 | 24 - June Shift - 1
Chapter : Work, Energy and Power | Topic : Work Done by a Variable Force
A particle experiences a variable force \(\tt \widehat{F}\) = \(\tt (4x \widehat{i} + 3y \widehat{j}) \) in a horizontal x-y plane. Assume distance in meters and force is newton. If the particle moves from point (1, 2) to point (2, 3) in the x-y plane; then Kinetic Energy changes by
Solution : C
W \(\tt \int_{}^{} \widehat{F}.\overrightarrow{dr} \)
=> \(\tt \int_{1}^{2} 4xdx + \int_{2}^{3}3y^{2}dy \)
=> \(\tt \large[2x^{2}]^{2}_{1}\) + \(\tt \large[y^{3}]^{3}_{2}\)
=> 2 x 3 + (27 - 8)
=> 25 J
W \(\tt \int_{}^{} \widehat{F}.\overrightarrow{dr} \)
=> \(\tt \int_{1}^{2} 4xdx + \int_{2}^{3}3y^{2}dy \)
=> \(\tt \large[2x^{2}]^{2}_{1}\) + \(\tt \large[y^{3}]^{3}_{2}\)
=> 2 x 3 + (27 - 8)
=> 25 J