Question

An automobile engine develops 100H.P. when rotating at a speed of 1800 rad/min. The torque it delivers is
(A) 3.33 W-s
(B) 200W-s
(C) 248.7 W-s
(D) 2487 W-s
​

Answer 1

D) is the right option I think

Answer 2

$\Large\underline{\underline{\sf \orange{Given}:}}$

• Power (P) = 100HP

in Watts 100HP = 74570Watss

• Speed of rotation $\sf{(\omega)}$ = 1800rpm

1800rpm in rps :-

$\implies{\sf \dfrac{2π}{60}×1800 }$

$\implies{\sf 60π\:rps}$

$\Large\underline{\underline{\sf \orange{To\:Find}:}}$

• Torque $\sf{(\tau)}$ = ?

$\Large\underline{\underline{\sf \orange{Formula\:Used}:}}$

$\large{\boxed{\sf \red{Power(P)=Torque (\tau).Speed(\omega) }}}$

$\Large\underline{\underline{\sf \orange{Solution}:}}$

$\implies{\sf \tau=\dfrac{74570}{60×π} }$

$\implies{\sf \tau=\dfrac{74570}{188.4}}$

$\implies{\sf \tau=395.8\:Nm}$

$\Large\underline{\underline{\sf \orangw{Answer}:}}$

⛬ Torque delivers is 395.8Nm