A particle of mass m is projected with speed u at angle θ with horizontal from ground. The work done by gravity on it during its upward motion is

Question

A particle of mass m is projected with speed u at angle θ with horizontal from ground. The work done by gravity on it during its upward motion is (A) (-m u2 sin 2 θ/2) (B) (m u2 cos 2 θ/2) (C) (m u2 sin 2 θ/2) (D) Zero

Tardigrade Admin · Accepted Answer

Height covered by projectile =(u2 sin 2 θ/2 g) W=-m g((u2 sin 2 θ/2 g)) =(-m u2 sin 2 θ/2)

Q. A particle of mass $m$ is projected with speed $u$ at angle $θ$ with horizontal from ground. The work done by gravity on it during its upward motion is

$\frac{- m u ^{2} s i n ^{2} θ}{2}$

$\frac{m u ^{2} c o s ^{2} θ}{2}$

$\frac{m u ^{2} s i n ^{2} θ}{2}$

Zero

Height covered by projectile $= \frac{u ^{2} s i n ^{2} θ}{2 g}$
$W = - m g (\frac{u ^{2} s i n ^{2} θ}{2 g})$
$= \frac{- m u ^{2} s i n ^{2} θ}{2}$

Q. A particle of mass m is projected with speed u at angle θ with horizontal from ground. The work done by gravity on it during its upward motion is

2−mu2sin2θ​

2mu2cos2θ​

2mu2sin2θ​