A body of mass 0.5 kg travels on straight line path with velocity v=(3 x2+4) m / s. The net workdone by the force during its displacement from x =0 to x =2 m is :

Question

A body of mass 0.5 kg travels on straight line path with velocity v=(3 x2+4) m / s. The net workdone by the force during its displacement from x =0 to x =2 m is : (A) 64 J (B) 60 J (C) 120 J (D) 128 J

Tardigrade Admin · Accepted Answer

v i =3(02)+4=4 ≅ x =0 v F =3(2)2 mid 4 ≅ x =2 =16 W =Δ K =(1/2) m (162-42) =(1/2) × (1/2)(256-16) =(240/4)=60 J

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

64 J

60 J

120 J

128 J

$v_{i} = 3 (0^{2}) + 4 = 4 ≅ x = 0$
$v_{F} = 3 (2)^{2} ∣ 4 ≅ x = 2$
$= 16$
$W = Δ K = \frac{1}{2} m (1 6^{2} - 4^{2})$
$= \frac{1}{2} \times \frac{1}{2} (256 - 16)$
$= \frac{240}{4} = 60 J$

Q. A body of mass 0.5kg travels on straight line path with velocity v=(3x2+4)m/s. The net workdone by the force during its displacement from x=0 to x=2m is :