Question

find the increase in kinetic energy of a body of mass 600g when its speed increases from 2m per second to 4m per second​

Answer 1

Answer:

3.6 Joules

Explanation:

Change in kinetic energy = $\frac{1}{2} m(v)^{2} -(u)^{2}$

Here,

m = mass  = 600 g = 0.6 kg(SI unit)

v = final velocity = 4m/s

u = initial velocity = 2m/s

Change in kinetic energy=

                                            $\frac{1}{2} *0.6*(4)^{2} -(2)^{2} \\= \frac{1}{2} *0.6*(16-4)\\=\frac{1}{2} *0.6*12\\= 6*0.6\\=3.6 J$

HOPE IT HELPS!

Answer 2

Answer:

Given :

➡️ mass of the body(m) = 600g

that is, mass = 600/1000kg = 0.6kg

➡️ initial velocity(u) = 2m per second

➡️final velocity(v) = 4m per second

To find :

➡️ final kinetic energy - initial kinetic energy

Solution :

initial kinetic energy = 1/2 × mass×initial velocity square = 2×2×1/2×0.6 Joule=1.2Joule

Hence, we have initial kinetic energy as 1.2 Joule

final kinetic energy = mass×final velocity=4×4×1/2×0.6 Joule = 4.8Joule

Hence, we have final kinetic energy as 4.8 Joule

final kinetic energy - initial kinetic energy = 4.8 Joule - 1.2 Joule

= 3.6Joule

Hence, the difference between final kinetic energy and initial kinetic energy is 3.6 Joule

formula of initial kinetic energy is 1/2× m × u square

formula of final kinetic energy is 1/2× m × v square

so, final kinetic energy-initial kinetic energy = (1/2×m×v square)-(1/2×m×u square)

= 1/2×m(v square - u square)

So, the answer you marked as brainliest is wrong as she/he done (v-u) square but it is v square - u square.