Question

A moving body of mass 30 kg has 60 J of kinetic energy. Calculate its speed. 

guys help me fast as much as possible
plz​

Answer 1

Given:-

• A moving body of mass 30 kg has 60 J of kinetic energy.

⠀

To find:-

• It's speed.

⠀

Solution:-

Here,

• Mass of the body (m) = 30 kg
• Kinetic energy (KE) = 60 J

⠀

Let,

• the velocity of the body be v.

⠀

We know that,

→ KE = 1/2 mv²

⠀

⇛ 60 = 1/2 × 30 × v²

⇛ 60 = 15v²

⇛ v² = 60/15

⇛ v² = 4

⇛ v = √4

⇛ v = 2 m/s

⠀

Hence,

• the speed is 2 m/s.

Answer 2

Given :-

• Mass of the body is 30 kg
• Kinetic Energy is 60 J

To Find :-

• Speed of that moving body

Solution :-

❒ As we know that , Kinetic energy is directly proportional to the mass of the object and to the square of its velocity . In the question we're given these values . So , let's solve !

$\sf \star \; k = \dfrac{1}{2}mv^{2} \; \star$

★ Where ,

• k is kinetic energy

• m is mass of body

• v is velocity of body

➼ Finding the speed of the moving body ::

$\sf \leadsto 60 = \dfrac{1}{2} \times 30 \times v^{2}$

$\sf \leadsto 60 = 15 \times v^{2}$

$\sf \leadsto v^{2} = \dfrac{60}{15}$

$\sf \leadsto v^{2} = 4$

$\sf \leadsto v = \sqrt{4}$

$\sf \leadsto v = 2 \; m/s$

∴ Speed of the moving body is 2 m/s