Question

From what height should a body of mass 40 kg fall in order to have sam
e kinetic energy as a body of
mass 1.96 kg travelling a
t 12 m/s?

Answer 1

i hope it helps......

Answer 2

Given,

Mass of 1st body, M = 40 kg,

Mass of 2nd body, m = 1.96 kg,

The velocity of the 2nd body, v = 12 m/s.

To find,

Height of 1st body to have the same energy as kinetic energy of 2nd body.

Solution,

Here, to find the height of the 1st body so that its energy equals the kinetic energy of the 2nd body, we can simply equate the energies of both bodies.

So,

The potential energy of 1st body = Kinetic energy of 2nd body

⇒ $Mgh=\frac{1}{2} mv^2$

Substituting the given values, we get,

$40\times 9.8\times h=\frac{1}{2} (1.96)(12)^2$

On simplifying,

$h=\frac{0.98\times 144}{40\times 9.8}$

⇒ h = 0.36 m.

Therefore, to have the same energy as that of the 2nd body, the 1st body should fall from a height of 0.36 m.