Question

given that the kinetic energy of an object is 100 J if the mass of object is 2 kg then find its speed​

Answer 1

Given :

• Kinetic energy of an body = 100 J
• Mass of an object, m = 2 kg

To find :

• Speed of an object, v

According to the question,

We know,

• Kinetic energy = ½ mv²

Now,

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

$: \implies \sf{100 = \dfrac{1}{2} \times 2 \times {v}^{2} }$

$: \implies \sf{100 = 1 \times {v}^{2} }$

$: \implies \sf{ \sqrt{100} = v }$

${ \underline{ \boxed{: \implies \sf \blue{10 = v}}}} \: \bigstar$

${ \therefore{ \underline{ \sf{So, the \: speed \: of \: an \: object \: is{ \textbf{ \textsf{10 m/s.}}}}}}}$

Answer 2

Answer:

Given :-

• The kinetic energy of an object is 100 J and the mass of object is 2 kg.

To Find :-

• What is the speed of an object.

Formula Used :-

${\red{\boxed{\large{\bold{K.E =\: \dfrac{1}{2}m{v}^{2}}}}}}$

where,

• K.E = Kinetic Energy
• m = Mass
• v = Speed or velocity

Solution :-

Given :

• Kinetic energy = 100 J
• Mass = 2 kg

According to the question by using the formula we get,

⇒ $\sf \dfrac{1}{\cancel{2}} \times {\cancel{2}} \times {v}^{2} =\: 100$

⇒ $\sf {v}^{2} =\: 100$

⇒ $\sf v =\: \sqrt{100}$

➠ $\sf\bold{\purple{v =\: 10\: m/s}}$

$\therefore$ The speed of an object is 10 m/s .