Question

A rifle can shoot a 0.004 kg bullet at a speed of 998 m/s. Find
the kinetic energy of the bullet.​

Answer 1

$\blue{\bold{\underline{\underline{Answer:}}}}$

$\green{\tt{\therefore{Kinetic\:energy=1992.008\:J}}}$

$\orange{\bold{\underline{\underline{Step-by-step\:explanation:}}}}$

$\green{\underline{\bold{Given :}}} \\ \tt: \implies Mass \: of \: bullet(m) = 0.004 \: kg \\ \\ \tt: \implies Speed \: of \: bullet(v) = 998 \: m/s \\ \\ \red{\underline{\bold{To \: Find :}}} \\ \tt: \implies Kinetic \: energy(K.E) =?$

• According to given question :

$\bold{As \: we \: know \: that} \\ \tt: \implies Kinetic \:Energy = \frac{1}{2} m {v}^{2} \\ \\ \tt: \implies Kinetic \:Energy = \frac{1}{2} \times 0.004 \times {998}^{2} \\ \\ \tt: \implies Kinetic \:Energy = \frac{1}{2} \times \frac{4}{1000} \times 996004 \\ \\ \tt: \implies Kinetic \:Energy = 0.002 \times 996004 \\ \\ \green{\tt: \implies Kinetic \:Energy = 1992.008 \: J}$

Answer 2

Explanation:

Given:-

mass=m=0.004kg

Speed (v)=998m/s

To find:-

kinetic energy =K.E

Solution:-

as we know that

${:}\longrightarrow$${\boxed{K.E={\frac{1}{2}}mv {}^{2}}}$

[By putting values]

${:}\longrightarrow$$K.E={\frac {1}{2}}×0.004×{998}^{2}$

${:}\longrightarrow$$K.E={\frac {1}{{\cancel{2}}}}×{\frac{{\cancel{4}}}{1000}}×996004$

${:}\longrightarrow$$K.E={\frac{2}{1000}}×996004$

${:}\longrightarrow$$K.E=0.002×996004$

${:}\longrightarrow$${\underline{\boxed{\bf {K.E=1992.008J}}}}$

$\therefore$$Kinetic\:energy=1992.008J$