Kinetic energy of an object is 25 j. Velocity is 5 m/s what will be its kinetic energy if velocity is doubles?

3 Answers
Feb 17, 2018

"100 J"100 J

Explanation:

"KE"=(1/2)*m*v^2KE=(12)mv2

Simple explanation :

Since the KE is proportional to velocity squared, if you increase the KE by a factor of 22, you increase vv by a factor of 2^2= 422=4

Detailed explanation :

25=0.5*m*(5^2)25=0.5m(52)

Find mm:

25=25m/225=25m2

m=2m=2

Hence the new KE:

"KE"=0.5*2*10^2KE=0.52102

"KE"=100 JKE=100J

Feb 17, 2018

The kinetic energy of body is "100 J"100 J.

Explanation:

"kinetic energy" =1/2 xx mxxv^2="25 J"kinetic energy=12×m×v2=25 J

v = "5 m/s"v=5 m/s

Let the mass of body be mm.

1/2xxmxxv^2=2512×m×v2=25

mxx5^2=50m×52=50

mxx 25=50m×25=50

m=50/25m=5025

or

m = "2 kg"m=2 kg

Now if velocity is doubled then

v'=2 * v

v'=2×x5

v' = "10 m/s"

The final kinetic energy =1/2xxmxx(v')^2

=1/2x×2x×10^2

=1/2x×2x×100

=100J

Feb 17, 2018

100J

Explanation:

We know that the equation for kinetic energy is

KE=1/2mv^2

Here, v=5, KE=25

:.25=1/2*m*5^2

25=1/2*25*m

:.m=2

So, the object's mass is 2kg.

If the velocity doubles, then v=5*2=10, and then

KE=1/2*10^2*2

KE=100J

So, the object's kinetic energy will be 100J.