Question 94: Work, Energy and Power & Circular Motion

Question

A body of mass $$0.5 \mathrm{~kg}$$ travels on straight line path with velocity $$v=\left(3 x^{2}+4\right) \mathrm{m} / \mathrm{s}$$. The net workdone by the force during its displacement from $$x=0$$ to $$x=2 \mathrm{~m}$$ is :

Accepted Answer

$$v = 3{x^2} + 4$$
at $$x = 0$$, $${v_1} = 4$$ m/s
$$x = 2$$, $${v_2} = 16$$ m/s
$$\Rightarrow$$ Work done = $$\Delta$$ kinetic energy
$$ = {1 \over 2} 	imes m\left( {v_2^2 - v_1^2} ight)$$
$$ = {1 \over 4}(256 - 16)$$
$$ = 60$$ J

Answer

64 J

Answer

60 J

Answer

120 J

Answer

128 J

Work, Energy and Power & Circular Motion

A body of mass $0.5 \mathrm{~kg} travels on straight line path with velocity v=\left(3 x^{2}+4\right) \mathrm{m} / \mathrm{s}. The net workdone by the force during its displacement from x=0 to x=2 \mathrm{~m}$ is :

Choose the correct answer: