Question

A moving body of mass 30 kg has 60 joule of kinetic energy. calculate its speed

Answer 1

Given:

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

To find:

The speed of a body

Solution:

K.E = 1/2 × m × v²

where,

K.E = kinetic energy of a body

m = mass of the body

v = velocity of the body

From given, we have,

K.E = 60 joule

m = 30 kg

⇒ 60 = 1/2 × 30 × v²

⇒ 2 × 60 = 30 × v²

⇒ 120  = 30 × v²

⇒ 4 = v²

∴ v = 2 m/s

Answer 2

Answer:

K.E = kinetic energy of a body

m = mass of the body

v = velocity of the body

From given, we have,

K.E = 60 joule

m = 30 kg

⇒ 60 = 1/2 × 30 × v²

⇒ 2 × 60 = 30 × v²

⇒ 120  = 30 × v²

⇒ 4 = v²

v=20ms-1

Step-by-step explanation: