Question

what is meant by mechanical energy?state the law of conservation of energy? show that when a body falls from a certain height the total mechanical energy remains conserved​

Answer 1

Explanation:

hlo mate here's your answer

Consider a body of mass m placed at A.

h = AB is the height of the body above the ground

u = 0 is initial velocity at A

v1 = velocity of body at C

v = velocity of body at B, i.e., just above the ground

(i) At point A

PEA = mgh

KEA = 0

Total mechanical energy at A, EA = PEA + KEA = mgh + 0 = mgh

(ii) At point C

v12-0 = 2gs

v12 = 2gs

KEC =

PEC = mg(h-s)

Total mechanical energy at C, EC = PEC + KEC = mg(h-s) + mgs = mgh

(iii) At point B

v2-02 = 2gh

v2 = 2gh

KEB =

PEB = 0

Total mechanical energy at B, EB = PEB + KEB = 0 + mgh = mgh

The total mechanical energy of the body at A, B and C (also at any other point in the path AB) is the same. So, the total mechanical energy of the body throughout the free fall is conserved.

i hope its help you mark as brainlist plz

Answer 2

Answer:

1. Mechanical energy is the total amount of kinetic energy and potential energy of an object that is used to do a specific work
2. The law of conservation of energy states that energy can neither be created nor destroyed - only converted from one form of energy to another
3. In the case of a freely falling body, it is the mechanical energy of the system that is conserved. Mechanical energy (E) is the sum of the potential energy (U) and the kinetic energy (K) of the freely falling body. Therefore, E=K+U=constant.