Question

(ii) The kinetic energy of a body is 500 joule. If velocity of the body is 10m sec then calculate the mass of the body
class-9th​

Answer 1

${\huge{\fcolorbox{blue}{purple}{ 10 kg}}}$

Given

Kinetic energy = 500 joule

Velocity = 10metre per second

We know that

$Kinetic \: energy = \frac{1}{2} \times m \times {v}^{2} \\ \\ 500 = \frac{1}{2} \times m \times {10}^{2} \\ \\ \frac{500}{100} \times 2 = m \\ \\ 5 \times 2 = m \\ \\ 10 \: kg = m$

$\bf\fbox\red{Hence the mass of the object is 10 kg}$

Answer 2

Given :-

Kinetic energy of the body = 500 J

Velocity of the body = 10 m/s

To Find :-

The mass of the body.

Analysis :-

Here we are given with the kinetic energy and the velocity of the body.

In order to find the mass of the body, substitute the given values from the question such that kinetic energy is equal to one by two into mass multiplied by velocity square.

Solution :-

We know that,

• v = Velocity
• KE = Kinetic energy
• m = Mass

$\underline{\boxed{\sf Kinetic \ energy= \dfrac{1}{2} mv^2}}$

Given that,

Kinetic energy (KE) = 500 J

Velocity (v) = 10 m/s

Substituting their values,

$\sf 500=\dfrac{1}{2} \times m \times 10^2$

$\sf 500=\dfrac{1}{2} \times m \times 100$

$\sf m=\dfrac{500}{100} \times 2$

$\sf m=5 \times 2$

$\sf m=10 \ kg$

Therefore, the mass of the body is 10 kg.