To determine kinetic energy of mass just before it hits the ground, first calculate potential energy the object possesses due to its position because PE is completely converted into KE just before the mass hits the ground.
Potential energy is given by equation:
Here, m is mass of object, g is gravitational acceleration constant (), and h is height of the object.
We have height (h) from which iron was dropped is 100 m. Substitute the values in equation (1) and calculate PE:
So, kinetic energy of the mass just before it hits the ground is .
Kinetic energy is given by equation:
Here, is speed of object.
With the known values calculate the value of:
Thus, speed of the iron mass is.
The internal energy change for a substance is given by equation:
Here, n is number of moles of substance, are final and initial temperatures of substance, and is molar heat capacity.
Convert the mass of iron (10 kg) to moles of iron using its molar mass.
If all the kinetic energy is transferred to its internal energy, we have
The molar heat capacity of iron () is.
Substitute the values in equation for and solve for final temperature:
So, the final temperature of the iron mass is.