Question

a man weighing 60kg runs with a speed of 5m/s to catch a bus ( g=10 m/s2). find the kinetic energy gained in him​

Answer 1

Given :

Mass of the man = 60kg

velocity of the man = 5m/s

To find :

The kinetic energy gained in hhim

Solution :

Kinetic energy is directly proportional to the mass of the object and to the square of its velocity

• Kinetic energy is a scalar quantity having magnitude
• The SI unit of Kinetic energy is Joule (J).
• The CGS unit of Kinetic energy is erg.

Kinetic energy is related with mass and velocity that is,

$\boxed{ \bf{K.E = \dfrac{1}{2} {mv}^{2} }}$

where,

• m denotes mass in kg
• v denotes velocity in m/s

Now substituting all the given values in the formula,

$:\implies{ \sf{K.E = \dfrac{1}{2} {mv}^{2} }}$

$:\implies{ \sf{K.E = \dfrac{1}{2} {(60)(5)}^{2} }}$

$:\implies{ \sf{K.E = 30 \times 25 }}$

$:\implies{ \underline{ \boxed{ \purple{ \sf{K.E = 750 \: J }}}}}$

thus, the kinetic energy gained in the man is 750 J.

Answer 2

Given data:

Mass of the man = 60kg

velocity of the man = 5m/s

To find:

The kinetic energy gained in him =?

Solution:

Kinetic energy is directly proportional to the mass of the object and to the square of its velocity

Kinetic energy is a scalar quantity.

The SI unit of Kinetic energy is Joule (J).

that is,

${ \bf{K.E = \dfrac{1}{2} {mv}^{2} }}$

where,

m denotes mass in kg

v denotes velocity in m/s

Now substituting all the given values in the formula,

$\implies{ \sf{K.E = \dfrac{1}{2} {mv}^{2} }}$

$\implies{ \sf{K.E = \dfrac{1}{2} {(60)(5)}^{2} }}$

$\implies{ \sf{K.E = 30 \times 25 }}$

$\implies{ \underline{ \boxed{ \sf{K.E = 750 \: J }}}}$

Thus, Your answer is 750J.

Hope so it will help........