Question

the mass of a person is 65 kg how fast should he Run so that his kinetic energy is 8125 j​

Answer 1

Answer:

$\bigstar{\bold{Velocity\:=\:15.8\:m/s}}$

Explanation:

$\Large{\underline{\underline{\bf{Given:}}}}$

• Mass(m) = 65 kg
• Kinetic energy (K.E) = 8125 J

$\Large{\underline{\underline{\bf{To\:Find:}}}}$

• Velocity of the body (v)

$\Large{\underline{\underline{\bf{Solution:}}}}$

→ The K.E of a body is given by the formula

   K.E = 1/2 × m × v²

→ Substituting the given datas we get the value of v

   8125 = 1/2 × 65 × v²

   v² = 8125/32.5

   v² = 250

   v =√250

$\boxed{\bold{Velocity\:=\:15.8\:m/s}}$

$\Large{\underline{\underline{\bf{Notes:}}}}$

→ The K.E of a body is defined as the energy possessed by a body by virtue of its motion.

  K.E  = 1/2 × m × v²

→ It is directly proportional to the mass and velocity of the body. It's unit is Joule (J)

Answer 2

Given ,

Mass (m) = 65 kg

Kinetic energy = 8125 J

We know that , the kinetic energy of a body is given by

$\boxed{ \sf{Kinetic \: energy = \frac{1}{2} \times m {(v)}^{2} }}$

Thus ,

8125 = 1/2 × 65 × (v)²

8125 = 37.5 × (v)²

(v)² = 8125/32.5

(v)² = 250

v = √250

v = 15.8 m/s

Therefore ,

The speed of a person is 15.8 m/s