Question

A piston moves a 25kg hammerhead vertically down 1m from rest to a

Answer 1

Answer:

Change in  energy will be 31.25 KJ

Explanation:

We have given mass of the piston = 25 kg

Initial velocity u = 0 m/sec

Final velocity v = 50 m/sec

Kinetic energy is given by $KE=\frac{1}{2}mv^2$

We have to find the change in energy

So change in energy = final KE - initial KE

$\Delta E=\frac{1}{2}m(v^2-u^2)$

$\Delta E=\frac{1}{2}25\times (50^2-0^2)=31250j=31.25KJ$

So change in  energy will be 31.25 KJ

Answer 2

Answer:

Total change in energy = 31 KJ.

Explanation:

Mass m=25 kg

Height h = 1 m

Initial velocity = 0

Final velocity = 50 m/s

Energy at initial condition

$E_1=mgh+\dfrac{1}{2}mv^2$

$E_1=25\times 10\times 1+0$

$E_1=250\ J$

Energy at final condition

$E_2=0+\dfrac{1}{2}\times 25\times 50^2$

$E_2=31250\ J$

So the change in energy = 31250 -250 J

The total change in energy = 31000 J