The heat required to change 1.25 kg of steak is 2825 kJ /kg.
<u>Explanation</u>:
Given, mass m = 1.25 kg, Temperature t = 100 degree celsius
To calculate the heat required,
Q = m
L
where m represents the mass in kg,
L represents the heat of vaporization.
When a material in the liquid state is given energy, it changes its phase from liquid to vapor and the energy absorbed in this process is called heat of the vaporization. The heat of vaporization of the water is about 2260 kJ/kg.
Q = 1.25
2260
Q = 2825 kJ /kg.
Mechanical energy equals the sum of potential and kinetic energy. During the process, all PE converts into KE, assuming air resistance is neglected. So, the mechanical energy does not change and is equal to the initial potential energy.
ME
=mgh
=0.005 x 9.81 x 3
=0.147J
Assuming you're working in a 3D cartesian coordinate system, i.e. each point in space has an x, y, and z coordinate, you add up the forces' x/y/z components to find the resultant force.
-- Toss a rock straight up. The kinetic energy you give it
with your hand becomes potential energy as it rises.
Eventually, when its kinetic energy is completely changed
to potential energy, it stops rising.
-- When you're riding your bike and going really fast, you come
to the bottom of a hill. You stop pedaling, and coast up the hill.
As your kinetic energy changes to potential energy, you coast
slower and slower. Eventually, your energy is all potential, and
you stop coasting.
-- A little kid on a swing at the park. The swing is going really fast
at the bottom of the arc, and then it starts rising. As it rises, the
kinetic energy changes into potential energy, more and more as it
swings higher and higher. Eventually it reaches a point where its
energy is all potential; then it stops rising, and begins falling again.
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