Question

A bullet of mass 30 g is moving with a velocity of 60 m/s find its kinetic energy in kilojoules​

Answer 1

Given :-

★ Mass of bullet, m = 30 g

★ Velocity of bullet = 60 m/s

To Find :-

★ Kinetic energy of the bullet in kilojoules.

Solution :-

We know,

✰ Kinetic Energy = ½ mv² ✰

Here,

m = 30 g

= 0.03 kg

On substituting the values, we get ___

Kinetic Energy = ½ mv²

⟹ Kinetic Energy = ½ × 0.03 × ( 60)²

⟹ Kinetic Energy = 54 Joules

⟹ Kinetic Energy = 0.054 KJ

Hence,

Kinetic energy of the bullet in kilojoules

= 0.054

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Note :-

1 Kilojoule = 1000 joules

1 kg = 1000 g

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$\bold\blue{ItzSilentColleen }$

Answer 2

Given :

• mass of bullet, m = 30 g = 0.03 kg
• velocity of bullet, v = 60 ms⁻¹

To find :

• kinetic energy of Bullet in Kilo joules

Formula required :

Formula for calculating kinetic energy

$\red{\bigstar}\boxed{\sf{E_k=\dfrac{1}{2} m v^2}}$

( where m is mass of object , E_(k) is kinetic energy of object and v is velocity of object )

Calculation :

Using formula for Kinetic energy

$\implies\sf{E_k=\dfrac{1}{2}mv^2}$

$\implies\sf{E_k=\dfrac{1}{2}\times 0.03\times (60)^2}$

$\implies\sf{E_k=\dfrac{1}{2}\times 0.03 \times 3600}$

$\implies\boxed{\boxed{\sf{\red{E_k=54 \;J =0.054\;KJ}}}}\red{\bigstar}$

therefore,

Kinetic energy of bullet is 0.054 Kilo joules.