Question

the kinetic energy of an object of mass m moving with velocity 5m/s is 25J what will be its kinetic energy when velocity is doubled? what will be the velocity if its increased 3times

Answer 1

3000 should be its velocity

Answer 2

$\tt{\underline{\underline{According\:to\:the\:Question}}}$    

Kinetic Energy

$\tt{\implies k =\dfrac{1}{2}\times mv^{2}}$  

Intial Kinetic energy = 25 Joule

Velocity is doubled

New Velocity (v’) = 2v

$\tt{\implies k =\dfrac{1}{2}\times m(2v)^{2}}$

$\tt{\implies k = 4\times\dfrac{1}{2}\times mv^{2}}$  

= 4 × 25j

= 100j

Velocity is made 3 times,

New Velocity ⇒ v^n = 3v

$\tt{\implies k = \dfrac{1}{2}\times m(3v)^{2}}$

$\tt{\implies k = 9\times\dfrac{1}{2}\times mv^{2}}$

= 9 × 25j

= 225j