Question

A 2 kg mass is moving at constant speed. The kinetic energy of the mass is 400 J. What is the speed of the mass? *

Answer 1

Answer:

Hence, speed of the body = 14.1421 Km/hour (approx.)

Explanation:

Let the velocity of the given mass be 'v' Km/hour

Then, given that,

Mass of body = 2 Kg (m)

Kinetic Energy of the body = 400 J (KE)

By formula, we know that,

KE = mv^2

By applying values, we get,

=> 400 = 2 × v^2

=> v^2 = 400/2 = 200

=> v = √200 = 14.1421

Hence, speed of the body = 14.1421 Km/hour (approx.)

Answer 2

K.E = 1/2 mv²

400 = 1/2 × 2 v²

v = √400

v = 20 ms-¹